John inherited the duchy from his mother, Duchess Isabelle, during the life of his father, Duke René of Anjou, also Duke of Lorraine and titular king of Naples. As heir-apparent of Naples, he was styled the Duke of Calabria and spent most of his time engaging in plots for the Angevin recovery of Naples. In 1460, he decisively defeated the king of Naples Ferdinand at Nola,^[3] but was unable to prevent others from coming to his aid. He was defeated at Troia in 1462^[4] and at Ischia in 1465. In 1466, the Catalans chose his father as King of Aragon, and he was created Prince of Girona, as heir-apparent. He went into Catalonia to press the family's claims, but died, supposedly by poison, in Barcelona.

In 1444, he married Marie de Bourbon (1428–1448),^[2] daughter of Charles I, Duke of Bourbon and Agnes of Burgundy, Duchess of Bourbon (and granddaughter to John the Fearless, and niece to Philip the Good, both Dukes of Burgundy and enemies and allies to her father). Marie was from the House of Bourbon and was the only Duchess consort of Lorraine from the reign of Valois-Anjou. The marriage contract was signed in April 1437, however, the ceremony took place around 1444 when she was older and would be able to consummate the marriage.

Marie and John had the following issue:

1. Isabelle (1445–1445)
2. Jean (1445–1471),
3. René (1446–1446)
4. Marie (1447–1447)
5. Nicholas (1448–1473)^[2]

Marie died giving birth to her last and only surviving child Nicholas; she died on July 7, 1448, and was buried at Meurthe-et-Moselle Lorraine, France.

John also had several illegitimate children:

• John (d. 1504), Count of Briey, married Nancy St. Georges
• Albert, seigneur d'Essey
• Jeanne d'Abancourt, married Achille, Bastard of Beauveu
• a daughter named Marguerite
• another daughter, married Jean d'Ecosse

• Dukes of Lorraine family tree

• Kekewich, Margaret L. (2008). The Good King: René of Anjou and Fifteenth Century Europe. Palgrave Macmillan.