The fort was built by the Portuguese under Philip I of Portugal in the 1580s on an earlier Omani fortress to protect the harbor after Muscat had twice been sacked by Ottoman forces.

Fort al-Jalali was restored in 1983 and converted into a private museum of Omani cultural history that is accessible only to dignitaries visiting the country.

[3] True to its name, Old Muscat is a natural port in a strategic location between the Persian Gulf and the Indian Ocean.

It lies on the coast of the Gulf of Oman on a bay about 700 metres (2,300 ft) long, protected from the sea by a rocky island.

[3] Al Jalali Fort lies on a rocky outcrop on the east side of the Muscat harbor.

[3] At this time the interior of Oman was ruled by an Arab Imam, but the coast on which Muscat lay was subject to the Persian King of Hormuz.

[8] In 1497 the Portuguese navigator Vasco da Gama found a route around the southern cape of Africa and east to India and the Spice Islands.

[10] On 10 August 1507, an expedition of six ships under Admiral Afonso de Albuquerque left the newly established Portuguese base on Socotra with Hormuz as the objective.

[12] At Qurayyat, which they took after a hard fight, the Portuguese mutilated their captives, killed the inhabitants regardless of sex or age, and despoiled and burned the town.

[10] Albuquerque signed a treaty under which the Portuguese were free of customs duties and could build a fort and trading factory at Hormuz.

[17] In 1520 a fleet of twenty three Portuguese ships anchored in the harbor en route from the Red Sea to Hormuz.

To make their base more secure, the Portuguese sent an engineer to build a fort to the west of the harbor, where al-Mirani stands today.

[23][24] In April 1552 an Ottoman fleet of twenty four galleys and four supply ships under Piri Reis left Suez en route to Hormuz, aiming to eliminate Portuguese presence in the region.

[27] In 1587 Captain Belchior Calaça[c] was sent to Muscat to build the fortress, which was named Forte de São João.

[30] After this the Portuguese built forts in other ports on the Omani coast, although they abandoned most of them in 1633–34, concentrating on defending Muscat.

[32] Muscat was a drain on Portuguese finances, with its requirement to maintain large military and naval forces to defend it.

Finding his power dwindling, Saif bin Sultan II asked for help from Nader Shah of Persia.

[40] The Persians made an unsuccessful attempt to take Muscat, defeated by a stratagem of the new Imam Sultan bin Murshid.

They took the town of Muscat, but the al-Jalali and al-Mirani forts held out and Saif bin Sultan II would not order them to yield.

[42] Ahmad bin Said al-Busaidi, the first ruler of the Al Said dynasty, blockaded Muscat and captured the forts in 1749.

[37] Early in 1781 two of Ahmad bin Said's sons, Sultan and Saif, took control of the forts of al-Mirani and al-Jalali.

When the governor of Muscat tried to recover the forts, Sultan and Saif began a damaging bombardment of the town.

While the ruler of Oman was away on a pilgrimage to Mecca early in 1803, his nephew Badr bin Saif made an attempt to get control of Fort Jalali.

The sultan of Oman, then residing in Zanzibar, arranged for Hamad to be seized and thrown in jail in Fort al Jalali.

[48] Colonel David Smiley, commander of the Sultan's armed forces at Muscat, called the prison "a veritable hellhole".

[32] In 1963 forty four prisoners escaped in a well-planned break-out, but most were quickly recaptured, handicapped by their weakened physical condition.

Around it on various levels are rooms, enclosures and towers accessible through a complex set of stairways that may have once had a defensive purpose.

[6] Exhibits include cannons at the gun ports with shot, ropes and firing equipment, as well as old muskets and matchlocks.

There are maps and historical illustrations, including a plaque that depicts the winds and the currents in Muscat bay.

The central square tower holds the main museum exhibits including rugs, pottery, jewelry, weapons, household utensils and incense holders.