According to Burke, Extinct and Dormant Baronetcies of England, Ireland and Wales, this William Barnham was Mayor of Norwich in 1652, while the Genealogical Record of the Barnum Family shows him as Mayor of Warwick in the same year. Both appear to be in error. Another William Barnham (1606-1678) held the office of Mayor in Norwich, while the reference to Warwick is apparently the result of a transposition of the names of the two cities.