As counts of Vexin, the kings of France were the vassals and advocates of the monastery of St. Denys. The saint's peculiar banner, which they received from the abbot, was of a square form, and a red or flaming colour. The oriflamme appeared at the head of the French armies from the 12th to the 15th century (Ducange sur Joinville, Dissert. xviii. p. 244 - 253).