Guy XIII de Laval, born Jean de Montfort, (1385- 14 August 1414, Rhodes) was seigneur of Laval and of Kergorlay. He was the son of and . Guy inherited the Laval title through his marriage on 22 January 1404 to Anne de Laval. As daughter and sole heir to , Anne was "dame de Laval", and one of the conditions of the marriage was that any children born to it would bear the name and arms of the House of Laval. (The same condition had already been applied to the marriage of with Mathieu II de Montmorency.) Nevertheless, Jean de Montfort renounced the name and title he had been born with to take up the name of Guy XIII de Laval, better to associate himself with his wife Anne's power. From the couple were descended several bishops and the greatest seigneurs of Brittany. Guy and Anne had 5 childr