In 1822, the Greek flag was adopted. It consists of nine equally sized blue and white horizontal stripes. On the upperleft-hand side is a white cross on a blue canton. The nine stripes symbolises the nine syllables of the motto "Freedom or Death" which was used during the 19th century during the Hellenic Revolution against the Ottoman Empire years. The "Freedom of Death" phrase encouraged the enslaved Greeks to fight slavery and gain their freedom after 400 years. It is also said that the nine lines reflects the word freedom because it contains nine letters. The lines were used because of their likeness of the Greek shoreline.

Another theory about the nine stripes is that they represent the nine muses (spirits or goddesses who express the arts through song and stage, traditional music and dance and writing), the goddesses of civilization and art.

It was in January 1822 when this design was accepted by the First National Assembly at Epidaurus. Over time, the colours used on the flag have had many interpretations; one being that blue represents the sea and the sky and white represents the crests of the waves and clouds. Blue is also the Greeks' traditional colour of clothes.

It has also been said that the flag was originally based on Byzantine Emperor Nicephorus II Phocas' coat of arms, which consists of alternating blue and white stripes, with a white cross on a canton.

Alternatively, a simpler explanation may be that the Greek flag's design was influenced by foreign flags.