Official Language: Arabic
Established: 751 AD/CE
Disestablished: 1970 AD/CE
Omani Azd used to travel to Basra for trade. Omani Azd were granted a section of Basra, where they could settle and attend their needs. Many of the Azd who settled in Basra became wealthy merchants and under their leader Muhallab bin Abi Sufrah started to expand the influence of power east towards Khorasan. Ibadi Islam originated in Basra with its founder Abdullah ibn Ibada around the year 650 CE, which the Azd in Iraq followed. Later, al-Hajjaj ibn Yusuf, the Umayyad governor of Iraq, came into conflict with the Ibadis, which forced them out to Oman. Among those who returned to Oman was the scholar Jabir ibn Zayd, an Omani Azdi. His return and the return of many other scholars greatly enhanced the Ibadi movement in Oman. The Imamate is estimated to have been established in 750 CE, shortly after the fall of the Umayyads.
Since its appearance, the Imamate governed parts or the whole of present-day Oman and overseas lands for interrupted periods of time. At its peak power, the Imamate was able to expel the Portuguese colonizers out of Oman and established a sea power that extended its empire to the Persian Gulf and East Africa during the 17th century. Even though the Imamate was isolated by the Hajar Mountains and the Empty Quarter desert, it had extensive global trade, as it exported dried dates, limes and handmade cotton textiles, and imported other products. The majority of trade happened with the Indian subcontinent.
In the mid-18th century, Ahmed bin Sa'id Al Bu Said, who came from a small village in the interior of Oman, expelled the Persian colonizers from Oman and became the elected Imam of Oman, with Rustaq as its capital. Upon Imam Ahmed's death in 1783, the sovereignty of Oman was divided between the coastal side, which followed a hereditary line of succession ruled by Albusaidi Sultans in Muscat, and the interior of Oman, which retained the elective Imamate and later moved its capital from Rustaq to Nizwa. The British empire was keen to dominate southeast Arabia to stifle the growing dominance of other European powers and to weaken the Omani empire during the 18th century. The British empire thus made the decision to back the Albusaidi Sultans of Muscat. The British empire established a series of treaties with the Sultans with the objective of advancing British political and economic interest in Muscat, in return for granting protection to the Sultans. The Sultanate eventually became increasingly dependent on British loans and political advice. There were often tensions between the imams and the sultans of Muscat. The dispute between the Imamate and the Sultanate was for the most part political. The Omanis in the interior believed that the ruler should be elected and rejected British growing political and economic control over Muscat and Oman. In 1913, Imam Salim ibn Rashid al-Kharusi instigated an anti-Muscat rebellion that lasted until 1920 when the Imamate established peace with the Sultanate through the signing of Treaty of Seeb. The treaty resulted in a de facto split between Oman and Muscat, wherein the interior part (Oman) was ruled by the Imamate and the coastal part (Muscat) was ruled by the Sultanate. Iraq Petroleum Company, which signed an oil concession with the Sultan of Muscat in 1937, deduced that oil was very likely to exist in the interior regions of Oman. In 1954, a new imam, Ghalib Alhinai, defended the Imamate from the attacks of the Sultanate of Muscat, which was backed by the British government. Sultan Said Bin Taimur of Muscat, with the direct support from the British forces, was able to defeat the Imamate in Jebel Akhdar War that lasted until 1959. The name Muscat and Oman was changed to the Sultanate of Oman in 1970.