FIG. 43. CAMBER CASTLE
[DEFENCES OF THE ESTUARIES OF THE THAMES, THE MEDWAY, ETC.]
Another group of defences erected at about this period was designed for the defence of the river Thames, the river Medway, and what in later times came to be known as the Port of London. These included block-houses at Gravesend, Tilbury, Higham, etc.
In 1536 Henry VIII repaired Queenborough Castle and brought its equipment up to date, so as to make it a useful part of the coast defence in this part of England.
Chatham Dockyard was founded by Queen Elizabeth, and for its protection she built Upnor Castle.
Upnor Castle.—This is a rather late form of castle, having been built in 1561 by Queen Elizabeth for the defence of the reach of the river Medway almost opposite the dockyard at Chatham. The engraving of it, here reproduced, shows it to have been a castellated building three stories in height, and furnished with towers at each end. A platform for guns, defended by a stockade, was made in front of the castle close to the edge of the river. The forts at Sheerness and Gillingham were built during the reign of Charles I.
FIG. 44. UPNOR CASTLE