Vatican City Flag - Official National Flag of the Holy See #303082 (License: Personal Use)

The flag of Vatican City consists of two vertical bands-gold (yellow) on the hoist side and white on the fly side-though often depicted horizontally for display purposes. Centered on the white band is the coat of arms of the Holy See: the papal tiara and two crossed keys (one gold, one silver), tied with a red cord, representing the keys to the Kingdom of Heaven entrusted to St. Peter. Adopted on June 7, 1929, following the Lateran Treaty, it is the world’s only national flag with a square aspect ratio (1:1).

Used on official Vatican websites, diplomatic contexts, encyclopedic entries, and educational resources about sovereign states or religious symbols; matches user intent for learning about national flags, Catholic symbolism, or Vatican sovereignty.