HIROHITO ), Emperor of Japan, was born on April 29, 1901, son of Emperor Yoshihito. While Crown Prince Hirohito visited Europe in 1921, and in that year the Emperor Yoshihito retired from public affairs on the ground of ill-health, leaving the government to Hirohito as prince regent. Hirohito married Princess Nagako on Jan. 26, 1924, and has two sons (b. 1933 and 1935) and three daughters (b. 1925, 1929, and 1931). A fourth girl died in 1928. For his regency, see JAPAN : History. He had been effectively the ruler of Japan for five years when he succeeded to the throne on Dec. 25, 1926. The new reign was officially designated the period of Showa (Light and Peace), and in the rescript issued by the new emperor on ascending the throne stress was laid on harmony at home and peace abroad.