A Papal Flag
of this Design was Introduced as the merchant flag of the Pontifical State at the beginning of the 19th Century. The colours are Those of the Keys of St Peter, which are the Keys to the Kingdom of Heaven and a symbol of Papal Authority. The Crossed Keys with the Papal Tiara Have Been the Emblem of the Papal State since the 14th Century. Although the official Proportions are 1:1, the Actual Flags Flown in the Vatican city are 2:3.