Capell was descended from a London Draper who served twice as lord mayor, represented the City in the Parliaments of 1491, 1512 and 1515, and acquired great estates in Essex and Hertfordshire.
As ‘Sir Arthur Capell, junior’, he was elected to Parliament in 1624 for St. Albans, where he had been nominated by the 2nd earl of Salisbury (William Cecil*), whose eldest daughter, a child of 12, was betrothed to his nephew, Arthur†, the heir to the Hadham estate.
Capell does not appear to have stood for Parliament again. It was reported in December 1628 that his courtship of an unnamed widow ‘went but coldly forward’, and he gave up entirely after breaking his shoulder in a traffic accident.
Capell maintained neutrality during the Civil War, corresponding with the parliamentarian (Sir) William Lytton* over the sequestration of the estates of his nephew, who had joined the royalists.
