John IV, Duke of Brittany
John IV the Conqueror KG, was Duke of Brittany and Count of Montfort from 1345 until his death and 7th Earl of Richmond from 1372 until his death.
Drawing c.1700 of English-made effigy, on white arcaded chest tomb, Nantes Cathedral. Original monument destroyed. Drawing by Roger de Gaignières.
John IV, Duke of Brittany, KG (right) jousting in Vannes, Brittany, with Thomas of Woodstock, 1st Duke of Gloucester, KG, c. 1480, Froissart's Chronicles
House of Montfort-Brittany
The House of Montfort-Brittany was a Breton-French noble family, which reigned in the Duchy of Brittany from 1365 to 1514. It was a cadet branch of the House of Dreux; it was thus ultimately part of the Capetian dynasty. It should not be confused with the older House of Montfort which ruled as Counts of Montfort.
The Solidor Tower in the estuary of the river Rance in Brittany was built between 1369 and 1382 by John V, Duke of Brittany to the Rance at a time when the city of Saint-Malo did not recognize his authority.