The Sultanate of Oman has one of the oldest civilizations in the Arabian Peninsula, dating back thousands of years with notable periods of greatness in the ancient world and in medieval times.

It is clear from recent archeological discoveries and research that early civilizations existed at least 5000 years ago.
Sumerian tablets refer to a country named "Magan" as a source of copper. It seems certain that they referred to Oman.Evidence from excavations near Sohar shows that the copper mining and smelting industry was well developed by the year 2000BC.
Frankincense from Dhofar, which was so important in the social religious life of ancient peoples also provides evidence of the existence of an early trading community. It is also clear that there were farming and fishing settlements from the earliest times.
The ancestors of present day Omanis are believed to have arrived in two waves of migration over a number of years, the first from Yemen and the second from northern Arabia at a time when various parts of the country were occupied by the Persians.
The call of the Prophet Mohammed to the Omanis to become Muslims altered the course of their history. It was in about 630 AD that Amr Ibn al-As arrived in Oman bearing a letter from the Prophet to Abd and Jaifar, the two sons of al-Julanda, who ruled Oman jointly. Having embraced Islam, they were instrumental in defeating the Persians.
The early Imamate in Oman arose out of a vision to create the true and ideal Muslim state. The first Ibadhi Imam, Julanda bin Mas'ud, was elected in 751 AD but he died in battle and it was not until 801 AD after a period of turmoil that Warith bin Kaab was elected. There then followed a period of peace, stability and prosperity lasting more than three hundred years.

Maritime trade flourished and Sohar became the greatest sea port in the Islamic world. As they traveled and traded, the Omanis spread the message of Islam, as well as Arab culture and language, reaching as far east as China.
Portuguese Occupation: In the early 16th century after the Portuguese under Vasco de Gama had discovered the sea route round the Cape of Good Hope to India, they occupied Muscat for a century and a half in order to dominate the trade which had until then been an Arab Monopoly. The Portuguese were expelled from Muscat in 1650 by Sultan bin Saif al-Yarubi.

The Ya'aruba Dynasty: Since the expulsion of the Portuguese no other foreign power has ever occupied Oman, apart from a brief period when the Persians made a partial occupation. The Ya'aruba Imams introduced a period of renaissance in Omani fortunes both at home and abroad, uniting the country and bringing prosperity. It was under the Ya'aruba dynasty that many of the imposing castles and beautiful buildings that have been restored recently, such as the fort at Nizwa and the Palace at Jabrin, were built.
Civil War: Unfortunately, on the death in 118 of the Imam, Sultan bin Saif II, civil war broke out over the election of his successor. Persian troops occupied Muttrah and Muscat but failed to take Sohar which was defended by Ahmad bin Said, who continued to fight the Persians and drive them from Oman after the civil war had ended.
The Al bu Said Dynasty In 1744 Ahmad bin Said, who was a man of outstanding personality and courage, was elected Imam. He faced a number of difficulties in reconciling the rival factions after the civil war, but he managed to build up the Omani navy into a power to be reckoned with, personally leading expeditions against pirates and driving the Persians out of Basra. When he died in 1783, his son Said was elected Imam but he was not popular, being replaced by his son Hamad, who had been de facto ruler in Muscat while his father remained in Rostaq. Hamad died suddenly in 1792 and his uncle, Sayyid Sultan bin Ahmed, assumed power until his death in 1804. He had exercised such tight control over Oman and trade in the Gulf that European powers dealt with him as the effective ruler of the country. Sayyid Sultan was succeeded by his son, Sayyid Said bin Sultan, who consolidated his father's achievements at home and abroad during his reign from 1804-1856. It was in this period that Oman reached its zenith as a regional power with possessions on both sides of the Gulf and in East Africa. Sayyid Said concentrated on developing his country's economy and commerce. He made Zanzibar his second capital and concluded agreements with the European powers, as well as sending a special envoy to the United States, making Oman the first Arab state to establish diplomatic relations with that country. Thereafter, however, there followed a period of decline and, at the time of the First World War, Oman's share of international commercial activities was very limited. Indeed, Oman remained largely isolated from the rest of the world until, in 1970, His Majesty Sultan Qaboos came to power. His Majesty's reign was the beginning of a bright new era that renewed Oman's historic glories and opened a new chapter of development, prosperity and social and economic progress.