A 1695 flag book by Carel Allard describes three flags used by the tsar of Muscovy: the tricolour with the double-headed eagle bearing a shield on its breast and wearing a golden crown over both of its heads, the same tricolour with a blue saltire over it, and a cross flag showing red and white quartering with a blue cross over all. The cross flag is depicted upon the Construction of Kronschloss Medal, which commemorates the construction of Fort Kronschlot (Kronschloss) in Kronstadt by Peter the Great in 1704, the colors of the flag being determined according to the hatchings engraved.