The national flag of Monaco has two equal horizontal bands of red (top) and white, both of which have been the heraldic colors of the House of Grimaldi since at least 1339. The present bicolor design was adopted on April 4, 1881, under Prince Charles III.
Monaco's original flag, which was similar to its current state flag but bore an older version of its coat of arms, was in use from the principality's early days (except during its annexation to France from 1793 to 1814) until the present simpler design was adopted in 1881.
Another design, the banner of the state arms (lozenges in the Grimaldi family colors, in heraldic terms "lozengy argent and gules"), was used at various times, particularly in the 1600s, as an unofficial flag, and still appears in some royal photographs. However, it has no designated use and does not represent any Monegasque official in particular.