Crompton was descended from the junior branch of a family which settled at Stone Abbey, Staffordshire, after the Reformation.
Seymour’s rehabilitation when he returned was rapid, and he succeeded his grandfather as the 2nd earl of Hertford in 1621. Crompton, who remained in his service, was returned to the 1624 Parliament for Great Bedwyn, a borough under Hertford’s control. He made no speeches, and his only committee nomination was for a private bill to enable Hertford and his brother, Sir Francis Seymour*, to sell certain manors (10 March).
