The flag of Galicia appeared for first time in the 19th century, probably based on the colours of the ancient medieval flags of the Kingdom of Galicia. Originally, the flag was probably a blue St Andrew's Cross over a white field - St Andrew is one of the most popular saints in Galicia. The Coat of Arms of Galicia was actually the former flag of the Kingdom of Galicia. Colors blue, white and gold were always related with Galicia. The chalice and the golden crosses on blue background have been its symbol since medieval times (13C). For some time it was thought that it was based on the flag of the maritime province of Corunna, but today it is known that the design is earlier.
During the 19th century many thousands of Galicians emigrated to the Americas; A Coruña was the main Galician port from which they departed. Tradition has it that the Galician emigrants thought that the A Coruña naval flag flying on the emigrant ships was actually the flag of Galicia. Therefore, when they arrived to the new world they started flying the A Coruña naval flag, believing this to be the flag of Galicia. Years later, the flag crossed the Atlantic back to the homeland, where it was officially adopted as the new flag of Galicia.
Originally, the flag for the maritime province of A Coruña was a blue St Andrew's Cross over a white field – St Andrew is one of the most popular saints in Galicia, where 72 parishes are devoted to him. This flag closely resembled the flag of Scotland – an interesting coincidence considering that, according to legend, the Gaelic peoples of the British Isles originally came from Galicia.
In 1891 the St Andrew's Cross flag had to be modified because it was causing confusion with the flag of the Imperial Russian Navy. Hence, it was decided to drop one of the arms of the cross. The result was the modern Galician flag.