The national flag of Greece, popularly referred to as the “sky-blue – white” or the “blue-white”, officially recognised by Greece as one of its national symbols, 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 symbolises Eastern Orthodox Christianity, the established religion of the Greek people of Greece and Cyprus. . 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. It was officially adopted by the First National Assembly at Epidaurus on 13 January 1822.

According to popular tradition, the nine stripes represent the nine syllables of the phrase “Freedom or Death”, the five blue stripes for the syllables “Ελευθερία” and the four white stripes “ή Θάνατος”. The nine stripes are also said to represent the letters of the word “freedom”. There is also a different theory, that the nine stripes symbolise the nine Muses, the goddesses of art and civilisation. 

Blue and white have been interpreted as symbolising the colours of the famed Greek sky and sea.