In 751 Ibadiyah Islamic sect began ruling via a succession of elected and hereditary Ibadite imams. The al-Bu Said Dynasty, which is still ruling the country, began 1749 when Ahmad Ibn Said became imam of Oman.

When Sultan Sa'id bin Sultan Al-Busaid died in 1856, his sons quarreled over his succession. As a result of this struggle, the empire - through the mediation of the British Government under the "Canning Award" - was divided in 1861 into two separate principalities: Zanzibar, with its East African dependencies, and Muscat and Oman.

Zanzibar paid an annual subsidy to Muscat and Oman until its independence in early 1964.

On December 20th 1951 the British recognized independence for the land called 'Muscat and Oman', although independence was only formal, in reality, Oman remained very much under British influence.

In 1964 Oil reserves were discovered, extraction began in 1967.

On July 23rd 1970 Sultan Said was overthrown by his own son, Qaboos ibn Said, in a palace coup. Said went into exile in London. Qaboos opened the political system, established a government, and started numerous development projects. In August of the same year the name of the country was changed to 'Sultanate of Oman'.

In 1971 Oman became member of the United Nations. Oman was a founding member of the six-nation Gulf Cooperation Council in 1981.

A consultative council, Majlis ash-Shura, with members from the region was established in 1990.

After the normalization of relations with Israel in September 1994, a demarcation line between Yemen and Oman was finalized in June 1995.

The sultan presented the basic laws, the Constitution of Oman, in 1996. It is based on Islam and local practice.

Sultan Qaboos announced in 1997 that women can stand for election to - and vote for - the majlis al-shura or Consultative Council.

Sources:
History of Nations, Lexicorient, BBC News