SIRHINDĪ, AḤMAD (AH 971–1034/1564–1624 CE), an eminent Indian Muslim Ṣūfī, known also as mujad-did-i alf-i thānī "renewer of the second millennium [of the Islamic era]"). He was a prolific writer on Islamic mysticism and theology. His celebrated collection of letters, addressed to his fellow Ṣūfīs as well as to a few officials of the state, was repeatedly hailed as a landmark in the development of Muslim religious thought in India.

Sirhindī 's religious activities were conducted within the Naqshbandī order of the Ṣūfīs, which was introduced into the subcontinent by Sirhindī's spiritual mentor, Muḥammad al-Bāqī Billah. Sirhindī became a prominent personality in the order, brought about an expansion of its influence in India and elsewhere, and attracted numerous disciples, whom he instructed in the Naqshbandī mystical doctrine. He devoted a...