William Sly spent most of his career with the Chamberlain's/King's men. However, it is unclear when he joined the company. Two pieces of evidence connect him with Philip Henslowe and the Rose playhouse: on 11 October 1594, Henslowe sold Sly "A Jewell of gowld seat wth A whitte safer" for 8s., which Sly repaid in eight payments over four months (Fol. 15); and an item labeled "Perowes sewt," tagged "which Wm Sley were" in the inventory lists made by Henslowe in 1598/9 (Greg, Papers (APX. I. i, p. 120). He was certainly a member of the Chamberlain's men when the second part of "The Seven Deadly Sins" was in their active repertory. He remained with the company after it became the King's men in 1603. He lived in the parish of St. Leonard's, Southwark, and his burial on 16 August 1608 is recorded in its register.
Porrex ("Envy"); Lord ("Lechery") in "The Second Part of the Seven Deadly Sins"
Actor list, Every Man in his Humour
Actor list, Every Man out of his Humour