The child, a short-lived boy, was given the title Duke of Brittany before his death in 1705.

He reigned briefly as Duke of Brittany from 990 to 992.

John V, Duke of Brittany built the keep in 1382-1383.

Conan was in fact the personal name of several Dukes of Brittany.

John V won the undisputed right to rule as Duke of Brittany.

The viscounts also fought with the Duke of Brittany in attempts to maintain their independence.

Buckingham could not join his allies who were to arrive in a fleet provided by the Duke of Brittany.

Alan succeeded his father as Duke of Brittany in 1008.

Peter was the Duke of Brittany of the time.

After 1420, the castle became the property of the Duke of Brittany.