The story of Oxfordshire parliamentary representation is dominated by the career—unrivalled during this period—of Sir Francis Knollys of Rotherfield Greys, who was returned to the senior county seat unchallenged in seven consecutive Parliaments. Vice-chamberlain of the Household and Privy Councillor from 1559, and lord lieutenant of the county from 1569, Knollys’s last appearance in Parliament was in 1593 at the age of 81. On his death in 1596, the senior county seat passed to his second but eldest surviving son William, who like his father, was a figure of both national and local importance, comptroller of the Household, Privy Councillor and joint lord lieutenant of the county. William Knollys held the senior seat in 1597 and 1601, thus giving the Knollys family a monopoly of the Oxfordshire senior seat in all the Parliaments of the reign except the first. On three occasions before the death of Sir Francis Knollys the family had also monopolized both county seats (1572, 1584 and 1593).

The remaining MPs were all county landowners who took turns to represent the shire. None of them sat for it more than once during this period. Two were national figures: Sir Richard Blount of Mapledurham (1563) was lieutenant of the Tower as well as lord lieutenant of the county; Sir Henry Norris I of Rycote, whose wife was a friend of the Queen, was a potential rival for the senior county seat. Returning from his embassy in France in 1570, he took the junior seat in 1571, but any threat to Knollys’s parliamentary supremacy in the shire was averted by Norris’s being given a peerage in 1572. Norris was made joint lord lieutenant of the county with Knollys in 1585. His son, Sir John Norris, a soldier, was returned as junior knight of the shire in 1589.

Thomas Brydges of Cornbury (1559) was a relative by marriage of his fellow MP, Edmund Ashfield of the Lodge, Ewelme Park, a follower of the Norris family. Sir Edward Unton, who replaced Blount at a by-election for the 1566 session of Parliament, had his main estate in neighbouring Berkshire but was also a considerable Oxfordshire landowner. Richard Fiennes of Broughton castle (1586), Sir Richard Wenman of Thame Park (1597) and Ralph Warcoppe of English (1601) were all country gentlemen with local offices.