Nawab Qasim Jan was a courtier in the royal courts of Mughal Delhi.
Soon he was given the title of Nawab and Khan, and given the region of Hateen near Gurgaon and thereafter he built his home close to Red Fort, in Ballimaran, Delhi, in the lane that is still known as Gali Qasim Jan, and also built mosque nearby known as Qasim Khani Mosque.
[3] Noted Urdu poet, Mirza Ghalib was married to Umrao Begum, daughter of Nawab Ilahi Bakhsh Khan (younger brother of the first Nawab of Loharu, Ahmad Baksh Khan); Ghalib ki Haveli, the poet's residence in Delhi, was in Gali Qasim Jan and is now a museum.
His son, Nawab Faizullah Beg, was a courtier during emperor Bahadur Shah Zafar's reign, and built a complex later known as Ahata Kaley Sahab, so named after saint Kaley Khan, who lived here for a while, after whom Delhi's Sarai Kale Khan is also named.
[1][4] Some of the prominent people who are linked to Qasim Jan lineage are Nawab of Loharu, Fakhruddin Ali Ahmed and Mirza Ghalib, whereas his own descendants[citation needed] were: