Vatican City
The name was first used in the Lateran Treaty, signed on 11 February 1929, which established the modern city-state. The name is taken from Vatican Hill, the geographic location of the state. "Vatican" is derived from the name of an Etruscan settlement, "Vatica" or "Vaticum" meaning garden, located in the general area the Romans called "vaticanus ager", "Vatican territory".
Flag of Vatican City
After the Lateran Treaty was signed in 1929, papal authorities decided to use the 1825 merchant flag as the state flag of the soon to be independent Vatican City state. However, the official drawing in the constitution used a drawing of the square 1862 infantry flag as a template. The treaty came into effect on 7 June 1929, and with it the newly-square Vatican flag.