Knighted in 1497 for valour in battle against the Scots, Cholmeley continued to serve as a soldier until 1513, becoming entrusted with many positions of responsibility for security of castles and fortifications in England. He was successful as a farmer and a shrewd investor in land, much increasing his family wealth. As Lieutenant of the Tower of London, he drew criticism for his reaction to the Evil May Day riots of 1517, when he ordered the firing of some of the Tower's artillery at the city to suppress rioting. He was also responsible for the rebuilding of the chapel of St Peter ad Vincula at the Tower. His illegitimate son, Roger Cholmeley, became Lord Chief Justice of the court of King's Bench.