sackville was a london barrister, and entered parliament in 1558. he was a member of the privy council in 1585. in 1586, he delivered the death sentence to mary, queen of scots. he served on diplomatic missions to the hague. in 1591, sackville became chancellor of the university of oxford. he served as lord high treasurer, a life appointment, from 1599 to 1608. he died of a stroke.