Leonard de Vries

Leonard de Vries was the leader of the Druids who worshipped the Cailleach.

Biography
De Vries lived at Boscombe Hall in 1978.

He knocked out the Fourth Doctor when he visited the Hall. De Vries and the Druids prepared him to be sacrificed, but they were forced to flee when Professor Amelia Rumford arrived.

Afterwards, Cessair of Diplos sent an Ogri to the Hall, which killed de Vries and his friend Martha. The Doctor and Rumford later discovered the bodies. (TV: The Stones of Blood)