Pevensey Castle is located at Pevensey, East Sussex. It is a Scheduled Monument in the care of English Heritage.
The castle is built on the site of the Roman fort of Anderitum. This, in the 3rd century, protected the southern coastline from Saxon raiders. It was abandoned soon after, when the Romans left the England. In 1042, the Anglo-Saxon Earl, Harold Godwinson, re-established the fort by digging defensive ditches within the walls. He abandoned the fort when he became Earl of East Anglia.
In the Summer of 1066, the English army encamped at the fort, but abandoned it when they moved further south. Duke William of Normandy landed at Pevensey Bay and found the fort abandoned, he dug a defensive ditch at the entrance to the castle.
Robert, count of Mortain was given Pevensey after the Norman Conquest. He repaired the walls to form the outer bailey. Later he built a rectangular stone keep.
The castle was besieged by William Rufus, loyal to King Stephen in the rebellion of 1088.
Improvements to the castle began in 1190 with the construction of the gatehouse. Later, in 1250, Peter of Savoy added three D shaped towers to the inner bailey.
Queen Elizabeth I ordered the castle to be demolished but this was ignored, but later the castle was fitted with Elizabethan gun emplacements and earthworks.
During the World War II the castle was used by the home guard and as a military camp for anti-aircraft troops. It also housed American and Canadian troops who were officially responsible for this section of coast in case of an invasion. As late as 1942 small additions were made to fortify the castle in case of German invasion across the Channel. A number of pillbox defences were built into the fabric of the castle.