Dating to the 12th century, it is one of the oldest heraldic symbols of any city in Portugal.

A golden mural crown of five towers (indicating capital and city status respectively) is surrounded by the collar of the Order of the Tower and Sword and by a white scroll with the motto "MUI NOBRE E SEMPRE LEAL CIDADE DE LISBOA" (lit.

The image on the coat of arms commemorates the voyage of the relics of Saint Vincent of Saragossa, patron saint of Lisbon, to the city from Cape St. Vincent in the Algarve, in the 12th century.

A shrine was erected over his grave, which continued to be guarded by flocks of ravens.

King Afonso Henriques ordered the body of the saint to be exhumed in 1173 and brought it by ship to the Lisbon Cathedral, still, allegedly, accompanied by the ravens.