Brackenbury was one of Richard III's close associates. He was treasurer of Richard's household when he was Duke of Gloucester. When King Edward died Brackenbury was almost certainly one of the Northerners who accompanied Richard to London. Shortly after Richard took the throne Brackenbury received a number of appointments, including Constable of the Tower of London. After the collapse of the Buckingham Revolt he was rewarded with large grants of land in the south-east of England forfeited by Rivers and the Cheney family and in 1484 was appointed sheriff of Kent.