[Footnote 21: 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 color.
The oriflamme appeared at the head of the French armies from
the xiith to the xvth century, (Ducange sur Joinville,
Dissert. xviii. p. 244 - 253.)]