Al Jalali Fort, or Ash Sharqiya Fort, is a fort in the harbor of Old Muscat, Oman. 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. The fort fell to Omani forces in 1650. During the civil wars between 1718 and 1747, the fort was twice captured by Persians who had been invited to assist one of the rival Imams. The fort was extensively rebuilt later.

Saif bin Sultan II was the sixth of the Yaruba dynasty of Imams of Oman, a member of the Ibadi sect. He held the position of Imam four times during a chaotic period of civil war and invasion by Persian forces.