Sayyid Ali Tirmizi, known as Pir Baba (1502-1583), was a Sufi saint born in Fergana (Uzbekistan) who settled in the Buner region of present-day Pakistan and played a major role in spreading Islam among the Yusufzai Pashtuns. He emphasized strict adherence to the Sharia and opposed the teachings of Pir Roshan. His shrine in Pacha Kalay village, Buner District, is one of the most important sites of Pashtun pilgrimage and hosts annual urs celebrations.