With the outbreak of World War Two, Ruperra Castle was requisitioned and from 1939 to 1946 a succession of Royal Army regiments, Signals, Mobile Bakery, Searchlights, Medical Corps, Indians, Dutchmen, were sent to Ruperra to be trained and moved on. At the end came German prisoners of war.

On December 6th 1941 when a British regiment of Searchlights were there, a large fire broke out in the castle caused by faulty electric wiring. Flames were

visible for miles around but in spite of the number of fire engines attending, the castle was gutted by the fire.

In 1956, the whole of the Tredegar estates of 53 000 acres were sold off, including the now ruined castle of Ruperra. The castle has remained in private ownership since then. However nothing has been done to stop its continued deterioration. As a result, in 1982, the south-eastern tower collapsed. There are large cracks in the other three.