The flag of Greece popularly referred to as the "blue-white" is based on nine equal horizontal stripes of blue alternating with white. There is a blue canton in the upper hoist-side corner bearing a white cross; the cross symbolizes Greek Orthodoxy, the established religion of the people of Greece and Greek Cypriots. There is a theory that the nine stripes symbolize the nine Muses, the goddesses of art and civilization (nine has traditionally been one of the numbers of reference for the Greeks). The official flag ratio is 2:3.
The blazon of the flag is Azure, four bars Argent; on a canton of the field a Greek cross throughout of the second. The shade of blue used in the flag has varied throughout its history, from light blue to dark blue, the latter being increasingly used since the late 1960s.
The above patterns were officially adopted by the First National Assembly at Epidaurus on 13 January 1822. Blue and white have many interpretations, symbolizing the colors of the famed Greek sky and sea (combined with the white clouds and waves), traditional colors of Greek clothes in the islands and the mainland, etc.