He was High Sheriff of Berkshire and Oxfordshire in 1546–7, and at the funeral of Henry VIII he bore the banner of the king and Queen Catherine Parr.
[2] Chamberlain was knighted by Queen Mary at Westminster on 2 October 1551, the day after her coronation, and he sat for Scarborough in the parliament which assembled on 5 September.
He was constituted governor of Guernsey in 1553, where he improved the works at Castle Cornet, and was returned for Oxfordshire to the parliaments which sat on 2 April and 12 November 1554.
[2] Although he was often absent from the Channel Islands, Chamberlain cooperated with William Wynter to stabilise the military position there against the French threat during the Italian War of 1551–59, paying attention to Alderney and Sark.
[4] Francis Chamberlain, who in 1555 was joined with him in the government of Guernsey, and who continued sole governor till his own death in 1570, was his eldest son.