Little is known of Kohat's early history. According to local lore, Kohat was founded by an ancient Buddhist king by the name of "Raja Kohat". Another Buddhist Raja named Adh is believed to have established his domain on the north side of the city. A fort, now in ruins, serves as a marker of their domain. The remains of this fort known as Adh-e-Samut, is possibly named after Buddhist Raja Adh. The fort is still fitted with weaponry from the Buddhist period. The Buddhist kings built roads, which were in use until the end of the Mughal rule.