Walmar Castle is the most southerly of the three Henrian coastal forts which protected the Downs, that sheltered strait lying between the coast and the Goodwin Sands. It stands a mile from Deal Castle, to which it was originally connected by earthworks, and was built at the same time. Though resembling Deal in principle, it is simpler in design. It consists of a squat cylindrical tower closely surrounded by a lower curtain, the latter projecting outwards in four semi-circular lobes to form a quatrefoil plan. It was a plan shared by Sandown Castle, the northern member of the group and now almost totally destroyed.
Walmer Castle stands in its entirety but, in contrast to Deal and most of the other Henrician forts, it austerity has been mellowed by conversion into a stately home. In 1708, the militarily redundant castle became the official residence of the Lord Warden of the Cinque Ports, a medieval office which has survived to the present day as an honorable sinecure.
The transformation to a mansion is all the more remarkable given that the low, curved, immensely thick walls cannot have lent themselves easily to such a purpose. Fine gardens now surround the castle and encroach upon its deep, stone-faced ditch, while many of the gun embrasures have been converted into windows.
When first built, Walmer exhibited the usual Henrician defensive arrangements. Cannon would have been mounted on the parapets of the central tower and outer curtain, a third tier of fire being provided at the level of the ditch by gun ports in the curtain. These gun ports are linked, as at Deal, by a continuous fighting gallery in the thickness of the wall. The central tower provided the main accommodation for governor and garrison. The lobe containing the entrance was heightened in the 1860s to provide further accommodation.
According to the Domesday Book, this was one of the strongholds founded by William Fitz Osbern, Earl of Hereford. Soon after the castle was granted to Ralph de Mortimer. Henry II captured the castle from Hugh de Mortimer in 1155, and it was here that Prince Edward obtained refuge following his escape from Hereford Castle in 1265.
The most notorious of the line was Roger Mortimer, first Earl of March, who played a leading part in the deposition and murder of Edward II. In concert with his lover, Queen Isabella, Mortimer ruled England for three years until being overthrown by the young Edward III. He died on the gallows at Tyburn and Wigmore was given to the Earl of Salisbury, but the Mortimers regained their lands and title by marriage. They served with distinction during the Hundred Years War, but in 1425, the Mortimer line died out and the castle more or less died with them.
The castle is in a very precarious condition nowadays, its walls overgrown or buried in debris, and threatening to crumble further unless essential work is carried out. If the remains were to be excavated and consolidated, Wigmore would be a castle of considerable interest, but at present there is just an atmosphere of desolation. It is a powerfully sited, motte and bailey stronghold with a lot of masonry still standing. The oval shell keep on the large motte incorporates Norman portions, but all the other stonework belongs to a reconstruction of about 1300, probably undertaken by the infamous Roger Mortimer. There are three towers on the line of the bailey curtain, two oblong and one half round. The largest tower contained a suite of chambers and is divided by a cross wall. Note the arch of the gatehouse, half buried in an accumulation of earth.