(1344-1393) Jean I de Bourbon-La Marche; became Count of Vêndome when his brother-in-law died in 1374. Accompanied Bertrand du Guesclin to Castile in 1366, on his campaign at the service of Enrique de Trastámara. Conde das Marchas Chronicle entries in which Jean I, Count de la Marche appears: Crónica de D. Pedro, ch. 36: 16