Adopted in 1911. The flag of Portugal has two vertical bands of green (hoist side, two-fifths) and red (three-fifths) with the national coat of arms (armillary sphere and Portuguese shield) centered on the dividing line. Explanations for the color meanings are ambiguous, but a popular interpretation has green symbolizing hope and red the blood of those defending the nation. (ref: CIA World Factbook) Note: Others claim that the color symbolism is meaningless. The flag was adopted by republican revolutionaries in 1910. The traditional Portuguese coat of arms has a long history, and evolved over at least six centuries.