Kasganj was founded by Nawab Yaqoot Ali Khan, a descendant of the Nawabs of Farrukhabad. The city was known as Yaqoot Ganj in the early sixteenth century, but it later became popularly known as Kasganj because it was established in a thick forest of kans, a vegetation grown abundantly here. The inscription regarding its establishment is still visible in the city's Jama Masjid (big mosque). It is said that the well-protected building at Tehsil Road which houses the tehsil was the residence of Nawab Yaqoot Ali Khan until it was acquired by the British after fall of Awadh. Later the city came into the hands of Kunwar Maharaj Singh Jain, then succeeded by late kunwar Bhartendra singh Jain the only Zamindars of the city.