Elwyn Treville

Elwyn Treville, 6th Marquess of Crantock (1670-1724) was the last remaining branch of the Treville family to directly hold the title of Marquess of Crantock. He married relatively late and produced only five daughters, Isolda, Rowena, Morwenna, Demelza and Senara.

Seeing that his title was threatening to die with him, he negotiated that it should be reawarded by the crown to his son-in-law, Marcus Layton on the proviso that he took the name Treville-Layton. After his death, the title therefore went to a minor branch of the Layton family.