The fort at Multan sits on a mound above the old city. Ranjit Singh Ji's army took it in June 1818 after a siege of several months under Misr Diwan Chand, having failed at it repeatedly since 1802. The great gun Zamzama was brought down for the work and cracked. Nawab Muzaffar Khan and several of his sons died in the breach rather than surrender.
Thirty years later the fort was the trigger for the end of the Sikh state. In April 1848 two British officers, Patrick Vans Agnew and William Anderson, arrived to install a replacement for Diwan Mulraj as governor. They were attacked and killed. Mulraj was drawn into the revolt that followed.
The siege of Multan ran from summer 1848 to January 1849. A shell reached the main magazine on 30 December 1848 and the explosion took a large part of the fort and the Jamia mosque with it. The Second Anglo-Sikh War ended at Gujrat weeks later and the Punjab was annexed in March 1849.
What is left on the mound is the shrine of Shah Rukn-e-Alam, the outer walls in fragments, and the site of the Prahladpuri temple. The fort as a fort was ended by that magazine.
Misr Diwan Chand was the general who took it, a Brahmin who had begun as a clerk in the ordnance department before Ranjit Singh Ji gave him an army. He took Multan in 1818, Kashmir in 1819 and Dera Ghazi Khan after that. He is the most successful commander the Sikh state produced and among the least remembered.
The revolt spread outward from the fort. Herbert Edwardes held the field against Mulraj with irregular levies through the summer of 1848 while the Company decided whether it was putting down a rebellion or fighting a war, and by the time the siege train came up the whole province was in it.
The fort is largely gone. The mound and the shrines on it are what remain, and the two sieges together took most of the rest.