He concluded a treaty with Maharaja Ranjit Singh for a joint expedition to Kashmir which was undertaken in 1812. `Ata Muhammad was defeated and replaced by Fateh Khan`s real brother, Muhammad `Azim Khan, but Fateh Khan did not fulfil the terms of the treaty, and the Sikh general, Diwan Mohkam Chand, seized Shah Shuja` who was brought to Lahore. Ranjit Singh took Attock in June 1813. Fateh Khan and his brother, Dost Muhammad Khan, made an attempt to regain the fort, but were defeated by Diwan Mohkam Chand. Recovery of Attock remained the dream of Fateh Khan till his death in 1818.
References :
1. Suri, Sohan Lal, `Udmat-ut-Twarikh. Lahore, 1885-89
2. Griffin, Lepel, Ranjit Singh. Oxford, 1905
3. Bhagat Singh, Maharaja Ranjit Singh and His Times. Delhi, 1990