The Medieval Tower: A refuge and a base for royal power
    When Richard the Lionheart (1189-99) came to the throne he departed on a crusade to the Holy Land leaving his Chancellor, William Longchamp, Bishop of Ely, in charge of the kingdom. Longchamp soon embarked on an enlargement and strengthening of the Tower of London, the first of a series of building campaigns which by about 1350 had created the basic form of the great fortress that we know today. The justification for the vast expenditure and effort this involved was the political instability of the kingdom and the Crown's continuing need for an impregnable fortress in the City of London.
    Longchamp's works doubled the area covered by the fortress by digging a new and deeper ditch to the north and east and building sections of curtain wall, reinforced by a new tower (now known as the Bell Tower) at the south-west corner. The ditch was intended to flood naturally from the river, although this was not a success. These new defences were soon put to the test when the King's brother, John, taking advantage of Richard's captivity in Germany, challenged Longchamp's authority and besieged him at the Tower. Lack of provisions forced Longchamp to surrender but the Tower's defences had proved that they could resist attack.
    The reign of the next king John (1199-1216) saw little new building work at the Tower, but the King made good use of the accommodation there. Like Longchamp, John had to cope with frequent opposition throughout his reign. Only a year after signing an agreement with his barons in 1215 (the Magna Carta) they were once more at loggerheads and Prince Louis of France had launched an invasion of England with the support of some of John's leading barons. In the midst of his defence of the kingdom, John died of dysentery and his son, Henry III, was crowned.
    With England at war with France, the start of King Henry's long reign (1216-72) could have hardly been less auspicious, but within seven months of his accession the French had been defeated at the battle of Lincoln and the business of securing the kingdom could begin. Reinforcement of the royal castles played a major role in this, and his work at the Tower of London was more extensive than anywhere other than at Windsor Castle. Henry III was only ten years old in 1216, but his regents began a major extension of the royal accommodation in the enclosure which formed the Inmost Ward as we know it today. The great hall and kitchen, dating from the previous century, were improved and two towers built on the waterfront, the Wakefield Tower as the King's lodgings and the Lanthorn Tower (rebuilt in the 19th century), probably intended as the queen's lodgings. A new wall was also built enclosing the west side of the Inmost Ward.
    By the mid 1230s, Henry III had run into trouble with his barons and opposition flared up in both 1236 and in 1238. On both occasions the King fled to the Tower of London. But as he sheltered in the castle in March 1238 the weakness of the Tower must have been brought home to him; the defences to the eastern, western and northern sides consisted only of an empty moat, stretches of patched-up and strengthened Roman wall and a few lengths of wall built by Longchamp in the previous century. That year, therefore, saw the launch of Henry's most ambitious building programme at the Tower, the construction of a great new curtain wall round the east, north and west sides of the castle at a cost of over Ј5,000. The new wall doubled the area covered by the fortress, enclosing the neighbouring church of St Peter ad Vincula. It was surrounded by a moat, this time successfully flooded by a Flemish engineer, John Le Fosser. The wall was reinforced by nine new towers, the strongest at the corners (the Salt, Martin and Devereux). Of these all but two (the Flint and Brick) are much as originally built. This massive extension to the Tower was viewed with extreme suspicion and hostility by the people of London, who rightly recognised it as a further assertion of royal authority. A contemporary writer reports their delight when a section of newly-built wall and a gateway on the site of the Beauchamp Tower collapsed, events they attributed to their own guardian saint, Thomas а Becket. Archaeological excavation between 1995 and 1997 revealed the remains of one of these collasped buildings.
    In 1272 King Edward I (1272-1307) came to the throne determined to complete the defensive works begun by his father and extend them as a means of further emphasising royal authority over London. Between 1275 and 1285 the King spent over Ј21,000 on the fortress creating England's largest and strongest concentric castle (a castle with one line of defences within another). The work included building the existing Beauchamp Tower, but the main effort was concentrated on filling in Henry III's moat and creating an additional curtain wall on the western, northern and eastern side, and surrounding it by a new moat. This wall enclosed the existing curtain wall built by Henry III and was pierced by two new entrances, one from the land on the west, passing through the Middle and Byward towers, and another under St Thomas's Tower, from the river. New royal lodgings were included in the upper part of St Thomas's Tower. Almost all these buildings survive in some form today.
    Despite all this work Edward was a very rare visitor to his fortress; he was, in fact, only able to enjoy his new lodgings there for a few days. There is no doubt though that if he had been a weaker king, and had to put up with disorders in London of the kind experienced by his father and grandfather, the Tower would have come into its own as an even more effective and efficient base for royal authority.
    King Edward's new works were, however, put to the test by his son Edward II (1307-27), whose reign saw a resurgence of discontent among the barons on a scale not seen since the reign of his grandfather. ............