René of Anjou was a prince of the Valois family who had a complicated range of titles and claims, including that of King of Naples, from which kingdom he was ejected by the House of Aragon by 1442. There is evidence that Barthélemy either went to Naples, or that his works were known there, as his influence has been detected in the work of the Neapolitan artists Colantonio and Antonello da Messina. René preferred to live in his territories in the South of France, or in the Loire Valley, and was a poet and amateur artist of some talent. For a long time he was thought personally responsible for the manuscript illuminations now generally attributed to Barthélemy. From about 1447 Barthélemy appears in surviving accounts as "peintre et varlet de chambre" – the same positions as Jan van Eyck held with Philip the Bold (and the Limbourg brothers had held with the Duke of Berry). A "varlet de chambre" was a court appointment of considerable status as a personal attendant to René. He travelled with René to Guyenne and on several occasions to Angers. Between 1447 and 1449 his workroom was next to René's private apartments, suggesting a considerable and unusual degree of closeness to his patron. His last appearance in the accounts is in 1469, when he was paid his own salary, plus that of three servants or assistants, and three horses. There is some evidence he lived until 1476.