Short answers, pulled from the story.
Geoffrey de Mandeville was the first Constable of the Tower of London, appointed by William the Conqueror in the 11th century, around 1068. The office is one of the oldest in England, dating back to within a few years of the Norman Conquest.
In the Middle Ages, the Constable of the Tower was responsible for building maintenance, soldiers' pay, supervision of the royal menagerie's Keeper of the King's Animals, and the custody of prisoners. He also held authority over London's Jewry until the expulsion of Jews in 1290, and could raise local militia forces as Lord Lieutenant of the Tower Hamlets.
The last official prisoners at the Tower of London were Ronnie and Reggie Kray, the London gangsters, held there for a few days in 1952 for refusing to report for National Service. They were sent to the Tower because it was the barracks of the 1st Battalion Royal Fusiliers, the unit to which they had been assigned.
At the annual Ceremony of the Constable's Dues, a large Royal Navy vessel presents the Constable with a barrel of rum, continuing a medieval tradition in which ships mooring at Tower Wharf surrendered a portion of their cargo in exchange for the protection of the Tower's cannon. In 2026, a hundred cadets from the Volunteer Cadet Corps led the ceremony to mark the organisation's 125th anniversary.
Eleanor de Clare was the only female Constable of the Tower of London, holding the post briefly in October 1326. She was the wife of Hugh Despenser and surrendered the Tower during the London Uprising, ending her short tenure.
Arthur Wellesley, the 1st Duke of Wellington, served as Constable of the Tower from 1825 to 1852, a tenure of approximately 27 years. During that time he drained the moat, removed the royal menagerie and record office, and reformed the Yeoman Warders by ending the practice of buying and selling positions.