Popham was the only son of Sir John Popham (1531–1607), of Wellington, Somerset and Littlecote, Berkshire (now Wiltshire), Speaker of the House of Commons, Attorney General and Lord Chief Justice of England, by his wife Amy Adams, daughter of Hugh Adams of Castleton, St Athan, Glamorgan.
[1] As a soldier he served under Robert Devereux, 2nd Earl of Essex (1566–1601) in Spain and was knighted by him at Cadiz in June 1596.
[1] In November 1640, due to the influence of his son-in-law Thomas Luttrell (1583–1644) of Dunster Castle, Somerset, Popham was elected MP for the Luttrell pocket borough of Minehead in the Long Parliament and sat until his death.
However, Popham's wife is also described as a daughter of John Dudley of Yanwath and an heiress of Thomas Sutton, founder of the Charterhouse.
[6] By his wife he had four sons and seven daughters, including; Popham died in 1644 and was buried at Stoke Newington on 15 August 1644, but in March 1647 was moved to Bristol.