Brothers Sir James (1637-1693 or 1694) and John (1643-1705) Hayes both held legal and political careers. Sir James Hayes studied at Corpus Christi College, Oxford University and was admitted to Lincoln's Inn in 1649 before being called to the bar in 1656. He served as a member of Parliament for Marlborough in 1659 and recorder of Marlborough that same year. He became secretary to Prince Rupert (1619-1682) in 1665 and was instrumental in the creation of the Hudson's Bay Company and gaining control over Canadian territory. Hayes became an original member of the Royal Society in 1663 and was knighted in 1670.

John Hayes benefited from his elder brother's influence, holding a variety of positions related to England's control of Ireland during the Protectorate, including a share of the aulnage farm. He later briefly served as Member of Parliament for Winchelsea in the early 1700s, giving up his position to his nephew and brother James' son, James Hayes (1676-circa 1731).

The younger James Hayes briefly held a Navy career at the instigation of his half-brother Lord Falkland. After Falkland's death in 1694 ended that influence, Hayes settled at the family country home, Bedgebury. He fell into a decline after severe financial difficulties, dying without issue sometime between March 1730 and December 1731.