Frederick I, Holy Roman Emperor

Frederick I Barbarossa (1122 – 10 June 1190) was a German Holy Roman Emperor. He was elected King of Germany at Frankfurt on 4 March 1152 and crowned in Aachen on 9 March 1152. He became King of Italy in 1155 and was finally crowned Roman Emperor by Pope Adrian IV on 18 June 1155. Two years later, the term "sacrum" (i.e. "holy") first appeared in a document in connection with his Empire. He was then also formally crowned King of Burgundy at Arles on 30 June 1178. He got the name Barbarossa from the northern Italian cities he attempted to rule. Barbarossa is "red beard" in Italian—a mark of both their fear and respect. In German, he was known as Kaiser Rotbart which has the same meaning.

Before his royal election, he was by inheritance Duke of Swabia (1147–1152, as Frederick III). He was the son of Duke Frederick II of the Hohenstaufen dynasty. His mother was Judith, daughter of Henry IX, Duke of Bavaria, from the rival House of Welf, and Frederick therefore descended from Germany's two leading families, making him an acceptable choice for the Empire's prince-electors.

Early years
Frederick was born in 1122. In 1147 he became Duke of Swabia, and shortly afterwards made his first trip to the East, accompanied by his uncle, the German king Conrad III, on the Second Crusade. The expedition proved to be a disaster, but Frederick distinguished himself and won the complete confidence of the king. When Conrad died in February 1152, only Frederick and the prince-bishop of Bamberg were at his deathbed. Both asserted afterwards that Conrad had, in full possession of his mental powers, handed the royal insignia to Frederick and indicated that Frederick, rather than Conrad's own six-year-old son, the future Frederick IV, Duke of Swabia, succeed him as king. Frederick energetically pursued the crown and at Frankfurt on 4 March 1152 the kingdom's princely electors designated him as the next German king. He was crowned King of the Romans at Aachen several days later, on 9 March 1152. Frederick I was of the Hohenstaufen family on his father's side and of the Welf family on his mother's side. These were the two most powerful families in Germany. The Hohenstaufens were often called Ghibellines, which derives from the Italianized name for the Weibling castle, the family seat in Swabia. The Welfs, in a similar Italianization, were called Guelfs.

The reigns of Henry IV, Holy Roman Emperor, and Henry V, Holy Roman Emperor, left the status of the German empire in disarray. Power had waned under the weight of the Investiture controversy. For a quarter of a century following Henry V's death in 1125 the German monarchy was largely a nominal title with no real power. The king was chosen by the princes, given no resources outside those of his own duchy, and prevented from exercising any real authority or leadership in the realm. The royal title was furthermore passed from one family to another to preclude the development of any dynastic interest in the German crown. When Frederick I of Hohenstaufen was chosen as king in 1152, the royal power had been in effective abeyance for twenty-five years, and to a considerable degree, for more than eighty years. The only real claim to wealth lay in the rich cities of northern Italy, which were still within the nominal control of the German king. The Salian line had died out with the death of Henry V in 1125. The German princes refused to give the crown to his nephew, the duke of Swabia, for fear he would try to regain the imperial power held by Henry V. Instead, they chose Lothair III (1125–1137), who found himself embroiled in a long-running dispute with the Hohenstaufens, and who married into the Welfs. One of the Hohenstaufens gained the throne as Conrad III of Germany (1137–1152). When Frederick Barbarossa succeeded his uncle in 1152, there seemed to be excellent prospects for ending the feud, since he was a Welf on his mother's side. But the Welf duke of Saxony, Henry the Lion, would not be appeased. He remained an implacable enemy of the Hohenstaufen monarchy. Barbarossa had the duchies of Swabia and Franconia, the force of his own personality, and very little else to construct an empire.

The Germany that Frederick tried to unite was a patchwork of more than 1600 individual states, each with its own prince. Few of these, such as Bavaria and Saxony, were large. Many were too small to pinpoint on a map. The titles afforded to the German king were "Caesar", "Augustus" and "Emperor of the Romans". By the time Frederick would assume these, they were little more than propaganda slogans with little other meaning. Frederick was a pragmatist who dealt with the princes by finding a mutual self-interest. Unlike Henry II of England, Frederick did not attempt to end medieval feudalism, but rather tried to restore it. But this was beyond his ability. The great players in the German civil war had been the Pope, Emperor, Ghibellines and the Guelfs. None of these had emerged the winner.

Rise to power
Eager to restore the Empire to the position it had occupied under Charlemagne and Otto I the Great, the new king saw clearly that the restoration of order in Germany was a necessary preliminary to the enforcement of the imperial rights in Italy. Issuing a general order for peace, he made lavish concessions to the nobles. Abroad, Frederick intervened in the Danish civil war between Svend III and Valdemar I of Denmark and began negotiations with the Eastern Roman Emperor, Manuel I Comnenus. It was probably about this time that the king obtained papal assent for the annulment of his childless marriage with Adelheid of Vohburg, on the grounds of consanguinity (his great-great-grandfather was a brother of Adela's great-great-great-grandmother, making them fourth cousins, once removed). He then made a vain effort to obtain a bride from the court of Constantinople. On his accession Frederick had communicated the news of his election to Pope Eugene III, but had neglected to ask for the papal confirmation. In March 1153, Frederick concluded the treaty of Constance with the Pope whereby, in return for his coronation, he promised to defend the papacy, to make no peace with king Roger II of Sicily or other enemies of the Church without the consent of Eugene and to help Eugene regain control of the city of Rome.

First Italian Campaign: 1154–55
Frederick undertook six expeditions into Italy. In the first, beginning in October 1154 his plan was to launch a campaign against the Normans under King William I of Sicily. He marched down and almost immediately began encountering resistance to his authority. Obtaining the submission of Milan, he successfully besieged Tortona in early 1155, razing it to the ground before moving to Pavia where he received the Iron Crown, and with it, the title of King of Italy. Moving through Bologna and Tuscany, he was soon approaching the city of Rome. There, Pope Adrian IV was struggling with the forces of the republican city commune led by Arnold of Brescia, a student of Abelard. As a sign of good faith, Frederick dismissed the ambassadors from the revived Roman Senate, and Imperial forces suppressed the republicans. Arnold was captured and hanged for treason and rebellion. Despite his unorthodox teaching concerning theology, Arnold was not charged with heresy.

As Frederick approached the gates of Rome, the Pope advanced to meet him. At the royal tent the king received him, and after kissing the pope’s feet, Frederick expected to receive the traditional kiss of peace. But Frederick had declined to hold the Pope’s stirrup while leading him to the tent, and so Adrian refused to give the kiss until this protocol had been complied with. Frederick hesitated, and Adrian IV withdrew, and after a day’s negotiation, Frederick agreed to perform the required ritual. Rome was still in an uproar over the fate of Arnold of Brescia, so rather than marching through the streets of Rome, Frederick and Adrian retired to the Vatican.

The next day, 18 June 1155, Adrian IV crowned Frederick I Holy Roman Emperor at St Peter's Basilica, amidst the acclamations of the German army. The Romans began to riot, and Frederick spent his coronation day putting down the revolt, resulting in the deaths of over 1,000 Romans, and many more thousands injured. The next day, Frederick, Adrian and the German army travelled to Tivoli. From there, a combination of the unhealthy Italian summer and the effects of his year long absence from Germany meant he was forced to put off his planned campaign against the Normans of Sicily. On their way northwards, they attacked Spoleto, encountered the ambassadors of Manuel I Comnenus, who showered Frederick with costly gifts, and at Verona, Frederick declared his fury with the rebellious Milanese before finally returning to Germany.

Disorder was again rampant in Germany, especially in Bavaria, but general peace was restored by Frederick's vigorous, but conciliatory, measures. The duchy of Bavaria was transferred from Henry II Jasomirgott, margrave of Austria, to Frederick's formidable younger cousin Henry the Lion, Duke of Saxony, of the House of Guelph, whose father had previously held both duchies. Henry II Jasomirgott was named Duke of Austria in compensation for his loss of Bavaria. As part of his general policy of concessions of formal power to the German princes and ending the civil wars within the kingdom, Frederick further appeased Henry by issuing him with the Privilegium Minus, granting him unprecedented entitlements as Duke of Austria. This was a large concession on the part of Frederick, who realized that Henry the Lion had to be accommodated, even to the point of sharing some power with him. He could not afford to make an outright enemy of Henry.

On 9 June 1156 at Würzburg, Frederick married Beatrice of Burgundy, daughter and heiress of Renaud III, thus adding to his possessions the sizeable realm of the County of Burgundy. In an attempt to create comity, Emperor Frederick proclaimed the Peace of the Land, written between 1152–1157, which enacted punishments for a variety of crimes, as well as systems for adjudicating many disputes. He also declared himself the sole Augustus of the Roman world, ceasing to recognise Manuel I at Constantinople.



Second, Third and Fourth Italian Campaigns: 1158–1174
The retreat of Frederick in 1155 forced Pope Adrian IV to come to terms with King William I of Sicily, granting to William I territories that Frederick viewed as his dominion. This aggrieved Frederick, and he was further displeased when Papal Legates chose to interpret a letter from Adrian to Frederick in a manner that seemed to imply that the imperial crown was a gift from the Papacy and that in fact the Empire itself was a fief of the Papacy. Disgusted with the pope, and still wishing to crush the Normans in the south of Italy, in June 1158, Frederick set out upon his second Italian expedition, accompanied by Henry the Lion and his Saxon troops. This expedition resulted in the revolt and capture of Milan, the Diet of Roncaglia that saw the establishment of imperial officers and ecclesiastical reforms in the cities of northern Italy, and the beginning of the long struggle with Pope Alexander III.

Pope Adrian IV’s death in 1159 saw the election of two rival popes; Alexander III and the antipope Victor IV. Both sought Frederick’s support, Frederick, busy with the siege of Crema, appeared unsupportive of Alexander III, and after the sacking of Crema demanded that Alexander appear before the emperor at Pavia and to accept the imperial decree. Alexander refused, and Frederick recognised Victor IV as the legitimate pope in 1160. In response, Alexander III excommunicated both Frederick I and Victor IV. Frederick attempted to convoke a joint council with King Louis VII of France in 1162 to decide the issue of who should be pope. Louis came near the meeting site but, when he became aware that Frederick had stacked the votes for Alexander, Louis decided not to attend the council. As a result the issue was not resolved at that time.

The political result of the struggle with Pope Alexander was that the Norman state of Sicily and Pope Alexander III formed an alliance against Frederick. In the meantime, Frederick had to deal with another rebellion at Milan, which saw the city surrender on 6 March 1162, and much of it destroyed three weeks later on the emperor’s orders. The fate of Milan saw the submission of Brescia and Placentia and many other northern Italian cities. Returning to Germany towards the close of 1162, Frederick prevented the escalation of conflicts between Henry the Lion from Saxony and a number of neighbouring princes who were growing weary of Henry's power, influence and territorial gains. He also severely punished the citizens of Mainz for their rebellion against Archbishop Arnold. The third visit to Italy in 1163 saw his plans for the conquest of Sicily ruined by the formation of a powerful league against him, brought together mainly by opposition to imperial taxes.

In 1164 Frederick took what are believed to be the relics of the "Biblical Magi" (the Wise Men or Three Kings) from the Basilica di Sant'Eustorgio in Milan and gave them as a gift (or as loot) to the Archbishop of Cologne, Rainald of Dassel. The relics had great religious significance and could be counted upon to draw pilgrims from all over Christendom. Today they are kept in the Shrine of the Three Kings in the Cologne cathedral. The death of the antipope Victor IV saw Frederick give his support to a new antipope, Paschal III, but he was soon driven from Rome which once again saw the return of Pope Alexander III in 1165.

Frederick in the meantime was focused on restoring peace in the Rhineland, where he organized a magnificent celebration of the canonization of Charles the Great (Charlemagne) at Aachen, done under the authority of the antipope Paschal III. Concerned over rumours that Alexander III was about to enter into an alliance with the Byzantine Emperor Manuel I, in October 1166, he embarked on his fourth Italian campaign, hoping as well to secure the claim of Paschal III, and the coronation of his wife Beatrice as Holy Roman Empress. This time, Henry the Lion refused to join Frederick on his Italian trip, tending instead to his own disputes with neighbors and his continuing expansion into Slavic territories in northeastern Germany. He began besieging Ancona in 1167, which had acknowledged the authority of Manuel I; at the same time, Frederick's forces achieved a great victory over the Romans at the Battle of Monte Porzio. Heartened by this victory, he lifted the siege of Ancona and hurried to Rome where he not only had his wife crowned empress, but he also received a second coronation at the hands of Paschal III. Unfortunately, his campaign was stopped by the sudden outbreak of an epidemic (malaria or the plague), which threatened to destroy the Imperial army and drove the emperor as a fugitive to Germany, where he remained for the ensuing six years. During this period, Frederick decided conflicting claims to various bishoprics, asserted imperial authority over Bohemia, Poland, and Hungary, initiated friendly relations with Manuel I, and tried to come to a better understanding with Henry II of England and Louis VII of France. Many Swabian counts, including his cousin the young Duke of Swabia, Frederick IV, died in 1167, so he was able to organize a new mighty territory in the Duchy of Swabia under his reign in this time. Consequently, his younger son Frederick V became the new Duke of Swabia in 1167, while his eldest son Henry was crowned King of the Romans in 1169, alongside his father who also retained the title.

Later years
With an increasing anti-German sentiment sweeping through Lombardy, which culminated in the restoration of Milan in 1169, in 1174, Frederick made his fifth expedition to Italy but was opposed by the pro-papal Lombard League (now joined by Venice, Sicily and Constantinople) which had previously formed to stand against him. The cities of northern Italy had become exceedingly wealthy through trade, and represented a marked turning point in the transition from medieval feudalism. While continental feudalism had remained strong socially and economically, it was in deep political decline by the time of Frederick Barbarossa. When the northern Italian cities inflicted a defeat on Frederick at Alessandria in 1175, the European world was shocked that such a thing could happen. With the refusal of Henry the Lion to bring help to Italy, the campaign was a complete failure. Frederick suffered a heavy defeat at the Battle of Legnano near Milan, on 29 May 1176, where he was wounded and for some time was believed to be dead. This battle marked the turning point in Frederick's claim to empire. He had no choice other than to begin negotiations for peace with Alexander III and the Lombard League. In the Peace of Anagni in 1176, Frederick recognized Alexander III as pope and in the Peace of Venice, 1177, Frederick and Alexander III were formally reconciled. The scene was similar to that which had occurred between Pope Gregory VII and Henry IV, Holy Roman Emperor at Canossa a century earlier.

The conflict was the same as that resolved in the Concordat of Worms. Did the Holy Roman Emperor have the power to name the pope and bishops? The Investiture controversy from previous centuries had been brought to a tendentious peace with the Concordat of Worms and affirmed in the First Council of the Lateran. Now it had recurred, in a slightly different form. Frederick had to humble himself before Pope Alexander III at Venice.

The emperor acknowledged the pope's sovereignty over the Papal States, and in return Alexander acknowledged the emperor's overlordship of the Imperial Church. Also in the Peace of Venice, a truce was made with the Lombard cities, which took effect in August 1178. But the grounds for a permanent peace were established only in 1183, when, in the Peace of Constance, Frederick conceded their right to freely elect town magistrates. By this move, Frederick recovered his nominal domination over Italy. This became his chief means of applying pressure on the papacy.

In a move to consolidate his reign after the disastrous expedition into Italy, he was formally crowned King of Burgundy at Arles on 30 June 1178. Although the German kings had traditionally automatically inherited the royal crown of Arles since the time of Conrad II, Frederick felt the need to be crowned by the Archbishop of Arles, regardless of his laying claim to the title from 1152.

Frederick did not forgive Henry the Lion for refusing to come to his aid in 1174. By 1180, Henry had successfully established a powerful and contiguous state comprising Saxony, Bavaria and substantial territories in the north and east of Germany. Taking advantage of the hostility of other German princes to Henry, Frederick had Henry tried in absentia by a court of bishops and princes in 1180, declared that imperial law overruled traditional German law, and had Henry stripped of his lands and declared an outlaw. He then invaded Saxony with an imperial army to bring his cousin to surrender. Henry's allies deserted him, and he finally had to submit in November 1181. Henry spent three years in exile at the court of his father-in-law Henry II of England in Normandy, before being allowed back into Germany. He finished his days in Germany, as the much-diminished Duke of Brunswick. Frederick's desire for revenge was sated. Henry the Lion lived a relatively quiet life, sponsoring arts and architecture.

Frederick's victory over Henry did not gain him as much in the German feudalistic system as it would have in English feudalistic system. While in England the pledge of fealty went in a direct line from overlords to those under them, the Germans pledged oaths only to the direct overlord, so that in Henry's case, those lower than he in the feudal chain owed nothing to Frederick. Thus, despite the diminished stature of Henry the Lion, Frederick did not gain his allegiances.

Frederick was faced with the reality of disorder among the German states where continuous civil wars were waged between pretenders and the ambitious who wanted the crown for themselves. Italian unity under German rule was more myth than truth. Despite proclamations of German hegemony, the pope was the most powerful force in Italy. When Frederick returned to Germany after his defeat in northern Italy, he was a bitter and exhausted man. The German princes, far from being subordinated to royal control, were intensifying their hold on wealth and power in Germany and entrenching their positions. There began to be a generalized social desire to "create greater Germany" by conquering the Slavs to the east.

Although it appeared that the Italian city states had achieved a measure of independence from Frederick as a result of his failed fifth expedition into Italy, (culminating in the Peace of Constance in 1183), the emperor had not as yet quite given up on his Italian dominions. In 1184, he had held a massive celebration when his two eldest sons were knighted, and where thousands of knights were invited from all over Germany. While payments upon the knighting of a son were part of the expectations of an overlord in England and France, only a "gift" was given in Germany for such an occasion.

Frederick's monetary gain from this celebration is said to have been modest. During this same year, Frederick again moved into Italy and this time he joined forces with the local rural nobility to reduce the power of the Tuscan cities. In 1186, he engineered the marriage of his son Henry to Constance of Sicily, heiress to the Kingdom of Sicily, over the objections of Pope Urban III.

Third Crusade and death
Pope Urban III died shortly after, and was succeeded by Gregory VIII, who was more concerned with troubling reports from the Holy Land than with a power struggle with Barbarossa. After making his peace with the new pope, Frederick vowed to take up the cross at the Diet of Mainz in 1188. Frederick embarked on the Third Crusade (1189), a massive expedition in conjunction with the French, led by king Philip Augustus, and the English, under Richard the Lionheart. He organized a grand army of 100,000 men (including 20,000 knights) and set out on the overland route to the Holy Land. However, some historians believe that this is an exaggeration and that the true figure might be closer to 15,000 men, including 3,000 knights.

The Crusaders passed through Hungary, Serbia and Bulgaria and then entered Byzantine territory, arriving at Constantinople in the autumn of 1189. Matters were complicated by a secret alliance between the Emperor of Constantinople and Saladin, warning of which was supplied by a note from Sibylla, ex-Queen of Jerusalem. When they were in Hungary, Barbarossa personally asked the Hungarian Prince Géza, brother of the king, Béla III of Hungary, to join the Crusade. The king agreed, and a Hungarian army of 2,000 men led by Géza escorted the German emperor's forces. The armies coming from western Europe pushed on through Anatolia (where they were victorious in taking Aksehir and defeating the Turks in the Battle of Iconium), and entered Cilician Armenia. The approach of the immense German army greatly concerned Saladin and the other Muslim leaders, who began to rally troops of their own to confront Barbarossa's forces.

On 10 June 1190, Emperor Frederick drowned in the Saleph river. He had decided to walk his horse through the river instead of crossing the bridge that had been too crowded with troops. The current was too strong for the horse to handle, and his suit armour was too heavy for him to swim in: both were swept away and drowned. Some historians believe he may have had a heart attack that complicated matters. Some of Frederick's men put him in a barrel of vinegar to preserve his body.

Frederick's death plunged his army into chaos. Leaderless, panicking, and attacked on all sides by Turks, many Germans deserted, were killed, or committed suicide. Only 5,000 soldiers, a small fraction of the original force, arrived in Acre. Barbarossa's son, Frederick VI of Swabia, carried on with the remnants of the German army, along with the Hungarian army under the command of Prince Géza, with the aim of burying the emperor in Jerusalem, but efforts to conserve his body in vinegar failed. Hence, his flesh was interred in the Church of St Peter in Antioch, his bones in the cathedral of Tyre, and his heart and inner organs in Tarsus.

The unexpected demise of Frederick left the Crusader army under the command of the rivals Philip II of France and Richard I of England, who had traveled to Palestine separately by sea, and ultimately led to its dissolution. Richard continued to the East where he defeated Saladin in many battles, winning significant territories along the shores of Palestine, but ultimately failed to win the war before he was forced to return to England (see Treaty of Ramla). He returned home after he signed the treaty under the terms of the agreement that Jerusalem would remain under Muslim control. However, the city would be open to Christian pilgrimages. Also, the treaty reduced the Latin Kingdom to a geopolitical coastal strip that extended from Tyre to Jaffa.

Frederick and the Justinian code
With the increase in wealth of the trading cities of northern Italy, a revival in the study of the Justinian Code occurred. This was a Latin legal system which had become extinct centuries earlier. Legal scholars renewed its application. It is speculated that Pope Gregory VII personally encouraged the Justinian rule of law, and had a copy of it. Corpus Iuris Civilis (Justinian Body of Civil Law) has been described as the greatest code of law ever devised. It envisaged the law of the state as a reflection of natural moral law, the principle of rationality in the universe. By the time Frederick assumed the throne, this legal system was well established on both sides of the Alps. He was the first to utilize the availability of the new professional class of lawyers. The Civil Law allowed Frederick to use these lawyers to administer his kingdom in a logical and consistent manner. It also provided a framework to legitimize his claim to the right to rule both Germany and northern Italy. In the old days of Henry VI and Henry V, the claim of divine right of kings had been severely undermined by the Investiture controversy. The Church had won that argument in the common man's mind. There was no divine right for the German king to also control the church by naming both bishops and popes. The institution of the Justinian code was used, perhaps unscrupulously, by Frederick to lay claim to divine powers.

In Germany, Frederick was a political realist, taking what he could and leaving the rest. In Italy, he tended to be a romantic reactionary, reveling in the antiquarian spirit of the age, exemplified by a revival of classical studies and Roman law. It was through the use of the restored Justinian code that Frederick came to view himself as a new Roman emperor. Roman law gave a rational purpose for the existence of Frederick and his imperial ambitions. It was a counterweight to the claims of the Church to have authority because of divine revelation. The Church was opposed to Frederick for ideological reasons, not the least of which was the humanist nature found in the revival of the old Roman legal system. When Pepin the Short sought to become king of the Franks, the church needed military protection. Pepin found it convenient to make an ally of the pope. Frederick desired to put the pope aside and claim the crown of old Rome simply because he was in the likeness of the greatest emperors of the pre-Christian era. Pope Adrian IV was naturally opposed to this view and undertook a vigorous propaganda campaign which was designed to diminish Frederick and his ambition. To a large extent, this was successful.

Charismatic leader
Historians have compared Henry II of England to Frederick Barbarossa. Both were considered the greatest and most charismatic leaders of their age. Each had a rare combination of qualities that made him appear superhuman to his contemporaries. Each possessed longevity, boundless ambition, extraordinary organizing skill, and greatness on the battlefield. Both men were handsome and proficient in courtly skills, without appearing effeminate or affected. Both came to the throne in the prime of manhood. Each had an element of learning, without being considered impractical intellectuals, but rather more inclined to practicality. Each found himself in the possession of new legal institutions which were put to creative use in governing. Both Henry and Frederick were viewed to be sufficiently and formally devout to the teachings of the Church, without being moved to the extremes of spirituality seen in the great saints of the twelfth century. In making final decisions, each relied solely upon their own judgment. Both were interested in gathering as much power as they could.

In keeping with this view of Frederick, his uncle, Otto of Freising, wrote an account of Frederick's reign entitled Gesta Friderici I imperatoris (Deeds of the Emperor Frederick). Otto died after finishing the first two books, leaving the last two to Rahewin, his provost. The text is in places heavily dependent on classical precedent. For example, Rahewin's physical description of Frederick:

reproduces word for word (except for details of hair and beard) a description of another monarch written nearly eight hundred years earlier by Sidonius Apollinaris.

Frederick's charisma led to a fantastic juggling act which over a quarter of a century, restored the imperial authority in the German states. His formidable enemies defeated him on almost every side, yet, in the end, he emerged triumphant. When Frederick came to the throne, the prospects for the revival of German imperial power were extremely thin. The great German princes had increased their power and land holdings. The king had been left with only the traditional family domains and a vestige of power over the bishops and abbeys. The backwash of the Investiture controversy had left the German states in continuous turmoil. Rival states were in perpetual war. These conditions allowed Frederick to be both warrior and occasional peace-maker, both to his advantage.

Legend
Frederick is the subject of many legends, including that of a sleeping hero, like the much older British Celtic legends of Arthur or Bran the Blessed. Legend says he is not dead, but asleep with his knights in a cave in the Kyffhäuser mountain in Thuringia or Mount Untersberg in Bavaria, Germany, and that when the ravens cease to fly around the mountain he will awake and restore Germany to its ancient greatness. According to the story, his red beard has grown through the table at which he sits. His eyes are half closed in sleep, but now and then he raises his hand and sends a boy out to see if the ravens have stopped flying. A similar story, set in Sicily, was earlier attested about his grandson, Frederick II. To garner political support the German Empire built atop the Kyffhäuser the Kyffhäuser Monument, which declared Kaiser Wilhelm I the reincarnation of Frederick; the 1896 dedication occurred on 18 June, the day of Frederick’s coronation.

In medieval Europe, the Golden Legend became refined by Jacopo da Voragine. This was a popularized interpretation of the Biblical end of the world. It consisted of three things: (1) terrible natural disasters; (2) the arrival of the Antichrist; (3) the establishment of a good king to combat the anti-Christ. These millennial fables were common and freely traded by the populations on Continental Europe. End-time accounts had been around for thousands of years, but entered the Christian tradition with the writings of the Apostle Peter. German propaganda played into the exaggerated fables believed by the common people by characterizing Frederick Barbarossa and Frederick II as personification of the "good king".

Frederick's uncle, Otto, bishop of Freising wrote a biography entitled The Deeds of Frederick Barbarosa, which is considered to be an accurate history of the king. Otto's other major work, The Two Cities was an exposition of the work of St. Augustine of Hippo of a similar title. The latter work was full of Augustinian negativity concerning the nature of the world and history. His work on Frederick is of opposite tone, being an optimistic portrayal of the glorious potentials of imperial authority. (See description supra.)

Another legend states that when Barbarossa was in the process of seizing Milan in 1158, his wife, the Empress Beatrice, was taken captive by the enraged Milanese and forced to ride through the city on a donkey in a humiliating manner. Some sources of this legend indicate that Barbarossa implemented his revenge for this insult by forcing the magistrates of the city to remove a fig from the anus of a donkey using only their teeth. Another source states that Barbarossa took his wrath upon every able-bodied man in the city, and that it was not a fig they were forced to hold in their mouth, but excrement from the donkey. To add to this debasement, they were made to announce, "Ecco la fica", (meaning "behold the fig"), with the feces still in their mouths. It used to be said that the insulting gesture, (called fico), of holding one's fist with the thumb in between the middle and forefinger came by its origin from this event.

Use by the National Socialists
The German invasion of the Soviet Union in 1941 was codenamed Operation Barbarossa by Adolf Hitler.

Issue
Frederick's first marriage, to Adelheid of Vohburg, did not produce any issue.

From his second marriage, to Beatrice of Burgundy, he had the following children:


 * 1) Sophie (1161–1187), married to Margrave William VI of Montferrat.
 * 2) Beatrice (1162–1174). She was betrothed to King William II of Sicily but died before they could be married.
 * 3) Frederick V, Duke of Swabia (Pavia, 16 July 1164 – 28 November 1170).
 * 4) Henry VI, Holy Roman Emperor (Nijmegen, November 1165 – Messina, 28 September 1197).
 * 5) Conrad (Modigliana, February 1167 – Acre, 20 January 1191), later renamed Frederick VI, Duke of Swabia after the death of his older brother.
 * 6) Gisela(October/November 1168–1184).
 * 7) Otto I, Count of Burgundy (June/July 1170 – killed, Besançon, 13 January 1200).
 * 8) Conrad II, Duke of Swabia and Rothenburg (February/March 1172 – killed, Durlach, 15 August 1196).
 * 9) Renaud (October/November 1173 – in infancy).
 * 10) William (June/July 1176 – in infancy).
 * 11) Philip of Swabia (August 1177 – killed, Bamberg, 21 June 1208) King of Germany in 1198.
 * 12) Agnes (1181 – 8 October 1184). She was betrothed to King Emeric of Hungary but died before they could be married.

Frederick Barbarossa in fiction

 * Cyrus Townsend Brady's Hohenzollern; a Story of the Time of Frederick Barbarossa (1901) begins with a dedication to "the descendants of the great Germanic race who in Europe, in America, and in the Far East rule the world".
 * Umberto Eco's novel Baudolino (2000) is set partly at Frederick's court, and also deals with the mystery of Frederick's death. The imaginary hero, Baudolino, is the Emperor's adopted son and confidant.
 * John Crowley's novel Little, Big (1981) features Frederick Barbarossa as a character in modern times, awoken from his centuries of sleep. In the book, he becomes the President of the United States and rules as a tyrant.
 *  The Land of Unreason, by L. Sprague de Camp and Fletcher Pratt, mentions the castle of the Kyffhäuser.
 * In The Thomas Crown Affair (1999 film), the title character is said to be in possession of "an ornament worn by Frederick Barbarossa at his coronation in 1152."
 * The video game Age of Empires II: The Age of Kings has a campaign which follows Fredrick Barbarossa from the period of his struggles in Germany to his death on the Third Crusade. It is of note that Barbarossa never appears as an actual unit in the game, though the objective of the final level (after his death) is to take a unit named "Emperor in a Barrel" to the Dome of The Rock in Jerusalem.
 * In the video game Stronghold Warchest, Emperor Frederick is an AI opponent that players can challenge in skirmish play.
 * Frederick is a character in the video game Stronghold: Crusader.
 * The video game Medieval II Total War: Kingdoms features Frederik Barbarossa in the crusade campaign. Barbarossa launches a crusade to the Holy land with 100,000 strong men. During the next 'turn,' he drowns in the sea and because of his death the crusade is canceled.
 * Andreas Seiler's novel Real Wizard (2008) is an attribution to the 1,000 year old myth, with aspects of life and death of the Emperor. It includes a generalised German history of unification as a background to the story. ISBN 978-0-646-49625-2
 * In The Man from U.N.C.L.E episode "The Deadly Game" (S1E05), former S.S. scientist Wolfgang Volp tries to revive Hitler from suspended animation; he refers to Hitler by the codename "Barbarossa".
 * In the movie Sword of War (also entitled Barbarossa), Barbarossa is one of the main characters, played by Rutger Hauer.