Bani Utub invasion of Bahrain

Bani Utub invasion of Bahrain led to the end of Persian rule in Bahrain; and the annexation of Bahrain by the Arabs.

Background
After the fall of the Safavid dynasty, Bahrain went through a period of anarchy, dismay, and self-rule in villages which made the country vulnerable to foreign invasions. Utub forces often attacked the island during this phase which made the spiritual leader of Bahrain, Sheikh Mohammed ibn Abdullah Al Majed, use the Huwala to combat the Utubs' attacks. These attacks continued throughout the early 18th century until the Utubs launched a full-scale invasion of the island and established a government loyal to the Sultan of Muscat. The Utubs were defeated and expelled by the Huwala forces loyal to Bahrain's spiritual leader who established a government headed by Sheikh Jabara Al-Holi (also known as Jubayr al-Holi). The Persian Afsharids led by former Safavid general Nader Shah invaded the island in 1737 and deposed Sheikh Jabara. Persian rule continued for 46 more years, with brief interruptions, until the Utubs finally took over the island in 1783.

Civil war and invasion
Sayid Majed ibn Sayid Ahmad Al-Jidhafsi was Bahrain's vice governor and the headman of Jidhafs who often clashed with his political nemesis, Ahmad ibn Muhammad Al-Biladi, the headman of the semi-autonomous village of Bilad Al-Qadeem. This rivalry reached its climax when an argument between the Al Khalifas who came to the island of Sitra to buy some supplies and a merchant escalated into a shoot out which resulted in the deaths of numerous Al Khalifas. Those who remained went back to Zubarah and informed their clan about the incident which caused outrage between the Utubs, causing them to send a naval fleet to Sitra with the intention of avenging their kins' deaths. After a disproportionate number of Sitra inhabitants were killed as a result of the rampage, the Utubs returned to Zubarah.

After news of the incident reached Bahrain's governor, Nasr Al-Madhkoor, he ordered a naval attack on Zubarah and sent numerous warships filled with well-equipped soldiers to fulfill this mission. However, the Utubs' spies infiltrated Al-Madhkoor's inner circle and as a result the Utubs crushed Al-Madhkoor's navy after plans of the attack reached them which resulted in a decisive Utub victory. Al-Madhkoor then headed to Iran to ask the troubled government, which was already suffering from its own internal issues, for help which did not arrive because of that country's bad conditions. Subsequently, Sayid Majed Al-Jidhafsi, who was substituting for Al-Madhkoor, personally asked the Al Khalifas and their allies to invade the Bahrain archipelago and promised them material aid and victory, should they do so. This action proved to have a lasting effect on the county and a civil war between the loyalist forces led by Sayid Majid Al-Jidhafsi and Madan Al-Jidhafsi, the Iranian governor's vizier and the rebels led by Ahmad Al-Biladi ensued as a result. The loyalists ultimately won the civil war.

However, by this time, the Al Khalifas and other Utubs had just entered the country, killed the vizier and successfully captured the islands of Bahrain from Nasr Al-Madhkur. The Al Khalifa family has ruled Bahrain ever since. The invasion was led by Ahmed bin Muhammad Al Khalifa, leading to him being named Ahmed Al Fateh ("Ahmed the Conqueror").

The Al Khalifa were supported by a naval fleet from Kuwait and several Bedouin clans based in Zubara in its invasion of Bahrain. These clans included the Al-Ma'awdah, Al-Fadhil, Al-Mannai, Al-Noaimi, Al-Sulaiti, Al-Sadah, Al-Thawadi, and other families and tribes who later settled in the island.

Aftermath
The Utubs (including the Al Khalifas) moved from their epicenter of Zubarah to Bahrain in 1797 after Zubarah was besieged by Saudi troops under the command of the emir of Al-Hasa, General Ibrahim ibn Ofaysan and left their territories in Qatar under the control of the Al Thani clan which eventually seceded from the Emirate of Al Khalifa and set on a quest to conquer all of the Qatar Peninsula. Persian plans to reinstate their control of Bahrain were never utilized, however, Bahrain became a tributary state of Persia in 1799 after soliciting the aid of Bushehr to expel the Omanis, a request that was granted. Oman retaliated by re-invading Bahrain and deploying a garrison at Arad Fort. The Utubs besieged the fort and re-expelled the Omanis who tried to invade Bahrain once again in 1802 but failed due to Saudi support of the Al Khalifas. The Saudis then deposed the Al Khalifas, annexed Bahrain into their emirate, and imposed their rule over the island for nine years. Without a central government after the Saudis withdrew from Bahrain, tensions rose and havoc ensued in many Shia villages, especially those bordering newly founded Sunni towns where bedouin tribes would sometimes attack and loot neighboring Shia villages, causing some of their inhabitants to immigrate to nearby areas and countries such as Qatif, Ahsa, Iraq, and Iran. The Al Khalifas retook Bahrain in 1820 with British aid after they entered a treaty relationship with Great Britain and restored order in the country. Sporadic attacks against the Shia Arabs continued until the early 20th century.

The Sunni Arabs eventually began tolerating their fellow Shia Arabs and their formerly religious-based razzias now became directed primarily at areas inhabited by the newly arrived Persian immigrants whom they termed "al-Sharshaniya", i.e., people of unrecognized foreign origins.