Boucicaut (bōōsēkō´), c.1366–1421, marshal of France and crusader against the Ottoman Turks, whose real name was Jean III le Meingre. Captured by Ottoman Sultan Beyazid I at Nikopol (1396), he was ransomed. He was governor (1401–7) of Genoa, then under French rule, was captured by the English at Agincourt (1415), and died in England. He wrote several ballads and other poems. He commissioned the book of hours that is named after him.