Chandragomin
A famous seventh-century Indian lay practitioner who challenged Chandrakirti to a debate that lasted many years. His writings include Twenty Verses on the Bodhisattva Vows (Skt: Bodhisattvasamvaravimshakah; Tib: jam chug sem pä dom pa nyi shu pa) and Letter to a Disciple (Skt: Shisyalekha; Tib: lob ma la tring pä tring yik).