Question: when did the tower of london stop being a prison

title: Tower of London
text: The beginning of the Tudor period marked the start of the decline of the Tower of London 's use as a royal residence . As 16th - century chronicler Raphael Holinshed said the Tower became used more as `` an armouries and house of munition , and thereunto a place for the safekeeping of offenders than a palace roiall for a king or queen to sojourne in '' . The Yeoman Warders have been the Royal Bodyguard since at least 1509 . During the reign of Henry VIII , the Tower was assessed as needing considerable work on its defences . In 1532 , Thomas Cromwell spent £ 3,593 on repairs and imported nearly 3,000 tons of Caen stone for the work . Even so , this was not sufficient to bring the castle up to the standard of contemporary military fortifications which were designed to withstand powerful artillery . Although the defences were repaired , the palace buildings were left in a state of neglect after Henry 's death . Their condition was so poor that they were virtually uninhabitable . From 1547 onwards , the Tower of London was only used as a royal residence when its political and historic symbolism was considered useful , for instance each of Edward VI , Mary I , and Elizabeth I briefly stayed at the Tower before their coronations .