Waziristan (Pashto and Urdu: وزیرستان, "land of the Wazir") is a mountainous region covering the former FATA agencies of North Waziristan and South Waziristan which are now districts of Khyber Pakhtunkhwa province of Pakistan. Waziristan covers some 11,585 square kilometres (4,500 sq mi). The area is populated by ethnic Pashtuns. It is named after the Wazir tribe. The language spoken in the valley is Pashto, predominantly the Waziri dialect. The region forms the southern part of Pakistan's Federally Administered Tribal Areas, which is now part of Khyber Pakhtunkhwa province.The 16th-century Pashtun revolutionary leader and warrior-poet Bayazid Pir Roshan, who wrote the oldest known book in Pashto, was based in Kaniguram, Waziristan.