On this day, August 21, 1415, the North African city Ceuta was conquered by Portuguese forces. Nowadays the city is Spanish, but its flag still looks very much Portuguese.

The characteristic black-white gyronny is taken from the flag of Lisbon, but with the coat of arms of Ceuta in the middle (looking almost identical to that of Portugal). The addition of this coat of arms almost makes this Spanish city flag more Portuguese than the flags of Portuguese cities....