At the start of his reign, Japan was already one of the great powers — the ninth-largest economy in the world, the third-largest naval power, and one of the four permanent members of the council of the League of Nations. He was the head of state under the limitation of the Constitution of the Empire of Japan during Japan's imperial expansion, militarization, and involvement in World War II. After the war, he was not prosecuted for war crimes as many other leading government figures were, and his degree of involvement in wartime decisions remains controversial among historians. During the postwar period, he became the symbol of the new state and Japan's recovery, and by the end of his reign, Japan had emerged as the world's second largest economy.
Incorporates material from Wikipedia