[1] His mother died in childbirth when he was five years old, after which his father remarried to Elizabeth Rhodes, who was a kindly stepmother to William and his sisters.

He is said to have acted as a Royalist agent in Germany and Denmark, in partnership with Henry Coventry, which ended in a bitter quarrel, and a duel.

In 1662 the bill of attainder against his father was reversed by Parliament, and he regained the title of Earl of Strafford and was invested as a Knight of the Garter in 1661.

[2] He led a rather "obscure, undistinguished and uninteresting life",[3] however his 1667 speech in the House of Lords was praiseworthy,[4] protesting against the banishment of Edward Hyde, 1st Earl of Clarendon, on the grounds that no crime had been proved against him; his attitude is the more creditable since Clarendon had been one of his father's bitterest enemies.

[5] He became a member of the Privy Council in 1674, and attended the crucial meeting in 1678 when Titus Oates first revealed his fabricated Popish Plot.