Jean II's career would see him campaigning across many of the Middle Ages' battlefields. He aided the Teutonic Knights in their struggles to Christianize the pagans of Prussia and Lithuania. Additionally, he fought with the Conquistadors in their quest against the Moors of Spain.

Ultimately Jean II found himself at the great battle of Agincourt in October 1415 against the arch enemy England. At Agincourt he commanded the French vanguard where he was captured by the English. He died in captivity in 1421 in Yorkshire, England.