John III, Count of Armagnac
In 1391, he had to leave for Italy in order to go to the assistance of Charles Visconti, Lord of Parma and husband of his sister, Beatrix of Armagnac. Visconti was in conflict with his acquisitive cousin Gian Galeazzo Visconti, later the duke of Milan, whose ambition was to control the whole of northern Italy.
On May 14, 1378, John III married Marguerite (1363–1443), countess of Comminges (1363–1443). They had two daughters: