The Portuguese Cannon This brass cannon was cast in the early 15th century, with the Royal Arms of Spain on its barrel. It was transported to the Portuguese colonies in south-east Asia before 1785. The cannon came into the possession of the King of Arakan, ruler of a state on the west coast of Burma. It was subsequently captured by the British during their invasion of Burma in 1885. The cannon was presented to the City of Edinburgh and placed on Calton Hill in 1887.