<P> Political tensions between Charles I and Parliament in the second quarter of the 17th century led to an attempt by forces loyal to the King to secure the Tower and its valuable contents, including money and munitions . London's Trained Bands, a militia force, were moved into the castle in 1640 . Plans for defence were drawn up and gun platforms were built, readying the Tower for war . The preparations were never put to the test . In 1642, Charles I attempted to arrest five members of parliament . When this failed he fled the city, and Parliament retaliated by removing Sir John Byron, the Lieutenant of the Tower . The Trained Bands had switched sides, and now supported Parliament; together with the London citizenry, they blockaded the Tower . With permission from the King, Byron relinquished control of the Tower . Parliament replaced Byron with a man of their own choosing, Sir John Conyers . By the time the English Civil War broke out in November 1642, the Tower of London was already in Parliament's control . </P> <P> The last monarch to uphold the tradition of taking a procession from the Tower to Westminster to be crowned was Charles II in 1660 . At the time, the castle's accommodation was in such poor condition that he did not stay there the night before his coronation . Under the Stuart kings the Tower's buildings were remodelled, mostly under the auspices of the Office of Ordnance . Just over £ 4,000 was spent in 1663 on building a new storehouse, now known as the New Armouries in the inner ward . In the 17th century there were plans to enhance the Tower's defences in the style of the trace italienne, however they were never acted on . Although the facilities for the garrison were improved with the addition of the first purpose - built quarters for soldiers (the "Irish Barracks") in 1670, the general accommodations were still in poor condition . </P> <P> When the Hanoverian dynasty ascended the throne, their situation was uncertain and with a possible Scottish rebellion in mind, the Tower of London was repaired . Gun platforms added under the Stuarts had decayed . The number of guns at the Tower was reduced from 118 to 45, and one contemporary commentator noted that the castle "would not hold out four and twenty hours against an army prepared for a siege". For the most part, the 18th - century work on the defences was spasmodic and piecemeal, although a new gateway in the southern curtain wall permitting access from the wharf to the outer ward was added in 1774 . The moat surrounding the castle had become silted over the centuries since it was created despite attempts at clearing it . It was still an integral part of the castle's defences, so in 1830 the Constable of the Tower, the Duke of Wellington, ordered a large - scale clearance of several feet of silt . However this did not prevent an outbreak of disease in the garrison in 1841 caused by poor water supply, resulting in several deaths . To prevent the festering ditch posing further health problems, it was ordered that the moat should be drained and filled with earth . The work began in 1843 and was mostly complete two years later . The construction of the Waterloo Barracks in the inner ward began in 1845, when the Duke of Wellington laid the foundation stone . The building could accommodate 1,000 men; at the same time, separate quarters for the officers were built to the north - east of the White Tower . The building is now the headquarters of the Royal Regiment of Fusiliers . The popularity of the Chartist movement between 1828 and 1858 led to a desire to refortify the Tower of London in the event of civil unrest . It was the last major programme of fortification at the castle . Most of the surviving installations for the use of artillery and firearms date from this period . </P> <P> During the First World War, eleven men were tried in private and shot by firing squad at the Tower for espionage . During the Second World War, the Tower was once again used to hold prisoners of war . One such person was Rudolf Hess, Adolf Hitler's deputy, albeit just for four days in 1941 . He was the last state prisoner to be held at the castle . The last person to be executed at the Tower was German spy Josef Jakobs who was shot on 15 August 1941 . The executions for espionage during the wars took place in a prefabricated miniature rifle range which stood in the outer ward and was demolished in 1969 . The Second World War also saw the last use of the Tower as a fortification . In the event of a German invasion, the Tower, together with the Royal Mint and nearby warehouses, was to have formed one of three "keeps" or complexes of defended buildings which formed the last - ditch defences of the capital . </P>

Why do they have high security at the tower of london today