Oman, a nation on the Arabian Peninsula, has terrain encompassing desert, riverbed oases and long coastlines on the Persian (Arabian) Gulf, Arabian Sea and the Gulf of Oman. The Wahiba Sands is a region of dunes inhabited by Bedouins. The port capital, Muscat, is home to the massive, contemporary Sultan Qaboos Grand Mosque, and the old waterfront Muttrah quarter, with a labyrinthine souk and busy fish market.
Oman is the site of pre-historic human habitation, stretching back over 100,000 years. The region was impacted by powerful invaders, including other Arab tribes, Portugal and Britain. Oman once possessed the island of Zanzibar, on the east coast of Africa as a colony.
The northern half of Oman (beside modern-day Bahrain, Qatar, United Arab Emirates, plus Balochistan and Sindh provinces of Pakistan) presumably was part of the Maka satrap (a provincial governor in the ancient Persian empire) of the Persian Achaemenid (dynasty rolling in Persia from Cyrus I to Cyrus III i.e 553 – 330 BC) Empire. By the time of the conquests of Alexander the Great, the satrapy may have existed in some form and Alexander is said to have stayed in Purush, its capital, perhaps near Bam, in Kerman province. From the 2nd half of the 1st millennium, BCE waves of Semitic speaking peoples migrated from central and western Arabia to the east.
The most important of these tribes are known as Azd. On the coast, Parthian and Sassanian colonies were maintained. From 100 BCE to 300 CE Semitic speakers appear in central Oman at Samad al-Shan and the so-called Pre-Islamic recent period, abbreviated PIR, in what has become the United Arab Emirates. These waves continue, in the 19th century bringing Bedouin ruling families who finally ruled the Gulf states.
Oman was exposed to Islam in 630, during the lifetime of the prophet Muhammad; consolidation took place in the Ridda Wars in 632.
In 751 Ibadi Muslims, a moderate branch of the Kharijites, established an imamate in Oman. Despite interruptions, the Ibadi imamate survived until the mid-20th century. Oman is currently the only country with a majority Ibadi population.
Several foreign powers attacked Oman. The Qarmatians controlled the area between 931 and 932 and then again between 933 and 934. Between 967 and 1053 Oman formed part of the domain of the Iranian Buyyids, and between 1053 and 1154 Oman was part of the Seljuk Empire. Seljuk power even spread through Oman to Koothanallur in South India.
In 1154 the indigenous Nabhani dynasty took control of Oman, and the Nabhani kings ruled Oman until 1470, with an interruption of 37 years between 1406 and 1443. The Portuguese took Muscat on 1 April 1515, and held it until 26 January 1650, although the Ottomans controlled Muscat from 1550 to 1551 and from 1581 to 1588. The latter recaptured Muscat from the Portuguese in 1650 after a colonial presence on the northeastern coast of Oman dating to 1508.
Turning the table, the Omani Yarubid dynasty became a colonial power itself, acquiring former Portuguese colonies in East Africa and engaging in the slave trade, centered on the Swahili coast and the island of Zanzibar.