Stjepan Vukčić Kosača

Stjepan Vukčić Kosača (Стјепан/Стефан Вукчић Косача; 1404–1466) was a medieval Bosnian duke that ruled a hereditary region in Hum. He was a member of the Kosača noble family. He was Grand Duke of Bosnia under the King Stephen Thomas, then, as the Kingdom of Bosnia started to dissolve under the Ottoman's military onset, he became semi-independent Hezeg, first under the Ottoman Empire, then Aragon and again the Ottoman Empire, and styled himself as Duke of Saint Sava.

It was Stjepan's title Herzeg (Herceg) that gave rise to the name of Ottoman sanjak established after 1482 when the Kosača family domain fell under Ottoman rule. The name remained since then and it's used for modern region of Herzegovina (Sanjak of Herzegovina was part of the Bosnia Eyalet, while modern Herzegovina is part of modern Bosnia and Herzegovina), and town of Herceg Novi in present day's Montenegro as well.

Early life
In May of 1404 Blagaj became one of the residences of Sandalj Hranić Grand Duke of Bosnia, later also seat of Stjepan Vukčić Kosača, after whom the some people called the Blagaj Fort Stjepan Grad. The Dubrovnik nobility accepted “Bosnae vojevodem Sandalj et consanguineous eius, knez Vukac, knez Vuk et Stephanum, filium knez Vukac” among the Ragusian nobles and granted them “domum in urbe” by charter dated 29 June 1419.

Upon Sandalj's death (15 March 1435), Tvrtko called an assembly to try to restore peace. As Sandalj had no heirs, his nephew Stjepan inherited the family domains. When Tvrtko died (1443), Stjepan did not participate in the election of Stephen Thomas and refused to recognize him. Stjepan supported Radivoj, the exiled brother and Ottoman ally.

Offensive into Zeta
At the end of September 1441 Kosača captured the territory of Upper Zeta on the left bank of Morača. Stefan Crnojević, who represented the whole Crnojević family, joined him in this campaign and was awarded by Kosača with control over five villages.

Aragonese vassalage
In 1443, the Papacy sent envoys to Stephen Tomas and Stjepan about a counter-offensive against the Ottomans, but the two were in the middle of a war. Ivaniš Pavlović, sent by Stephen Tomas, attacked Stjepan Vukčić. Stephen Tomas had at the same time been recognized by John Hunyadi, so Stephen turned to Alfonso V, who made him "Knight of the Virgin", but did not give him troops.

On 15 February 1444, Stephen signed a treaty with Alfonso V, King of Aragon and Naples, becoming his vassal in exchange for king's help against Stjepan's enemies, namely King Stephen Thomas of Bosnia, Duke Ivaniš Pavlović and Venice. In the same treaty Stjepan promised to pay regular tribute to Alfonso instead of paying the Ottoman sultan as he had done until then.

Falling out with Stephen Thomas
Being a staunch supporter and adherent of the Bosnian Church, Stjepan Kosača would eventually come to fall out with the Bosnian king Stephen Thomas who, albeit earlier confessing to the Bosnian Church himself, had pledged his allegiance with the Roman Catholic pope to contend the heretic beliefs emanating from within its denomination.

Temporary peace and Ottoman plundering
In 1446 the two rivals had made peace, with Stjepan Vukčić recognizing Stephen Thomas as king, and the pre-war borders were restored. Peace was sealed through the marriage between Stjepan Kosača's daughter Catherine and Stephen Thomas in May 1446. Catherine converted into Roman Catholicism. The Ottomans were displeased with the peace as their interest lay in dividing Bosnia. Despot Đurađ Branković was also displeased due to Srebrenica issue. In 1448, the Turks sent an expedition to plunder King Stephen Tomas lands, they also plundered Stjepan Vukčić's lands. Stjepan Vukčić sent envoys to Đurađ Branković, to try to improve the relations between the two.

Herzog and Srebrenica conflict
The same year Stjepan Vukčić assumed the title "Herceg (Duke) of Hum and the Coast", dropping "Duke of Bosnia". A year later, in 1449, he had changed it into "Duke of Saint Sava", after the Serbian saint whose relics lay in Mileševa in the east of his province. This title had a considerable public relations value since Sava's relics were considered miracle-working by people of all Christian faiths in the region and tied in with a boost of relations between him and Đurađ Branković; that same year a war broke out over Srebrenica between Despot Đurađ and Stephen Thomas, in which Stjepan sided with Đurađ Branković.

Siege of Dubrovnik
In 1451 Stjepan Vukčić attacked Dubrovnik, and laid siege to the city. He had earlier been made a Ragusan nobleman and, consequently, the Ragusan government now proclaimed him a traitor. A reward of 15,000 ducats, a palace in Dubrovnik worth 2,000 ducats, and an annual income of 300 ducats was offered to anyone who would kill him, along with the promise of hereditary Ragusan nobility which also helped hold this promise to whoever did the deed. Stjepan was so scared by the threat that he finally raised the siege.

Ottoman threat
In the early 1460s, Herceg Stjepan controlled of all of today's Herzegovina as far north as Glamoč, but Nevesinje and Gacko were under the control of the Ottoman Empire. Kosača knew he would soon face Ottoman attack so he asked Venetians to allow Skanderbeg's forces to cross their territory to help him. Venetians allowed Skanderbeg to cross their territory to help Kosača, but Skanderbeg failed to carry out his promises.

Mahmud Pasha's invasion
After taking the Kingdom of Bosnia in 1463, Mahmud Pasha also invaded Herzegovina and besieged Blagaj, after which Stjepan conceded a truce by sending his youngest son as a hostage to Istanbul, and ceding all of his lands to the north of Blagaj to the Empire.

Stjepan Vukčić died in 1466, and was succeeded by his eldest son Vladislav Hercegović.

Aftermath and legacy
In 1482 Vladislav Hercegović was overpowered by Ottoman forces led by his brother, Stjepan Vukčić's youngest son, Hersekzade Ahmed Pasha, who converted to Islam prior to that. Herzegovina was organized into a province (the Sanjak of Herzegovina), which later became one of the sanjaks of the Bosnia Eyalet (1580).

Stjepan founded the Zagrađe Monastery near his realm's seat in Herceg Novi, modern-day Montenegro, and the Serbian Orthodox monastery of Savina, also near Herceg Novi..

Issue
Stjepan Vukčić was married three times. In 1424, he married Jelena, daughter of Balša III of Zeta (and granddaughter of his aunt, Jelena Balšić). His wife died in 1453. Two years later, he married Barbara (possibly del Balzo). She died in 1459. His final marriage, in 1460, was to a German woman named Cecilie.

With his first wife Jelena, he had at least four children:
 * Catherine (1424–1478), married King Stephen Thomas of Bosnia in 1446
 * Vladislav Hercegović (c. 1427–1489), Duke of St. Sava, Lord of Krajina, married Kyra Ana, daughter of Georgios Kantakuzenos in 1455
 * Vlatko Hercegović (c. 1428–1489), Duke of St. Sava, married an Apulian noblewoman
 * Hersekzade Ahmed Pasha (c. 1430–1515), baptized Stjepan; the youngest son of Stjepan Vukčić, whom Sultan Mehmed II took as a hostage, became a Muslim in the Sultan's service. He became the Grand Vizier and Grand Admiral to the Sultan, married Sultan Bayezid II's daughter, Fatima, in 1482; and had descendants by her.

Stjepan and his second wife Barbara had a short-lived son (born in 1456) and a daughter named Mara.