Fort al-Mirani is a Portuguese fort built on top of an earlier fortress in 1587. Alongside Fort al-Jalali, Fort al-Mirani was intended to defend the harbor city from potential advancement from Ottoman forces in the late sixteenth century. While Muscat was largely under Portuguese control during this period, the Ottomans intermittently gained power and in the early seventeenth century, the English and Dutch began to enter the fray to gain control of the protected harbor. In 1622, a Persian-English Force took Hormuz forcing the Portuguese to fortify the forts around Muscat to rebuff a potential attack. In 1649, under the forms of Sultan bin Saif, Omani forces wrested power over Muscat from the Portuguese. In the eighteenth century, civil disputes over the Imamate as well as advancements by Persian forces in 1738 and 1743 would involve Fort al-Mirani. In 1749, Fort al-Mirani came under control of Ahmad bin Said al-Busaidi, the first ruler of the Al Said dynasty which continues to rule the Sultanate of Oman. It is reportedly the first to have used cannons in the Sultanate of Oman.