A government-sponsored ceremony marking 30 years of Emperor Akihito's reign was held Sunday at the National Theatre of Japan in Tokyo ahead of his abdication on April 30. Here is a look at the major events related to him:

Dec. 23, 1933 -- Born as the eldest son of Emperor Hirohito and Empress Nagako, posthumously called Emperor Showa and Empress Kojun, respectively.

(At 2 years old, December 1935)
[Photo supplied by the Ministry of the Imperial Household]

September, 1939 -- World War II begins.

Aug. 15, 1945 -- Emperor Hirohito tells the nation over radio of Japan's surrender in the war.

(At 12 years old and calligraphy "Construct a nation of peace" in sixth grade, 1946)

Nov. 10, 1952 -- Becomes crown prince after coming-of-age at 18.

(At the Tokyo Lawn Tennis Club, August 1958)

March 30-Oct. 12, 1953 -- Visits Europe and the United States, attends the coronation of Queen Elizabeth II in place of his father.

April 10, 1959 -- Marries Michiko Shoda, becoming the first crown prince, and later the first emperor, to be married to a commoner.

Feb. 23, 1960 -- First son, Prince Naruhito, born.

Nov. 30, 1965 -- Second son, Prince Fumihito, born.

April 18, 1969 -- Daughter, Princess Sayako, born.

(At the Nasu Imperial Villa, July 1978)

Jan. 7, 1989 -- Ascends to throne upon the death of Emperor Hirohito. Prince Naruhito becomes crown prince.

Jan. 8, 1989 -- The Heisei era begins.

June. 29, 1990 -- Prince Fumihito marries Kiko Kawashima.

July 10, 1991 -- Visits areas affected by volcanic eruption of the Fugen peak of Mt. Unzen in Shimabara, Nagasaki Prefecture.

Oct. 23, 1991 -- Princess Mako born to Prince Fumihito and Princess Kiko -- the first grandchild of Emperor Akihito and Empress Michiko.

Oct. 23-28, 1992 -- Becomes the first emperor to visit China.

June 9, 1993 -- Crown Prince Naruhito marries Masako Owada.

Dec. 29, 1994 -- Princess Kako born to Prince Fumihito and Princess Kiko -- the second grandchild of the imperial couple.

Jan. 31, 1995 -- Visits Hyogo Prefecture areas hit by the Great Hanshin Earthquake on Jan. 17.

July-August, 1995 -- Visits memorial sites in Nagasaki, Hiroshima, Okinawa and Tokyo as the year marks 50 years since the end of World War II.

Dec. 1, 2001 -- Princess Aiko born to Crown Prince Naruhito and Crown Princess Masako -- the third grandchild of the imperial couple.

Jan. 18, 2003 -- Undergoes surgery to remove cancerous prostate gland.

June 27-28, 2005 -- Visits Saipan to honor the souls of war victims 60 years after the end of WWII.

Nov. 15 -- Princess Sayako marries Yoshiki Kuroda, a Tokyo metropolitan government official, and relinquishes her royal status as stipulated by law.

Nov. 24 -- A government panel on imperial succession crafts a final report that proposes allowing females or heirs of female lineage to ascend the throne.

Sept. 6, 2006 -- Prince Hisahito born to Prince Fumihito and Princess Kiko -- the fourth grandchild and the first grandson of the imperial couple -- marking the first birth of a male imperial family member in 41 years.

Feb. 18, 2012 -- Undergoes heart bypass surgery.

April 8-9, 2015 -- Visits Palau to pay tribute to the war dead 70 years after the end of WWII.

Aug. 15 -- States "deep remorse" over World War II for the first time at an annual memorial ceremony for the war dead.

Aug. 8, 2016 -- Releases video message expressing desire to abdicate and pass the throne on to Crown Prince Naruhito.

[Photo supplied by the Imperial Household Agency]

June 9, 2017 -- Special legislation to enable Emperor Akihito to abdicate enacted.

Sept. 3 -- Princess Mako's planned engagement to Kei Komuro, a fellow International Christian University alumnus, announced.

Dec. 1 -- Imperial House Council meeting decides that Emperor Akihito will step down on April 30, 2019, with Crown Prince Naruhito ascending the throne the following day.

Feb. 6, 2018 -- Imperial Household Agency announces Princess Mako and Komuro will postpone their wedding due to "lack of preparation."

September 2018 -- Visits areas affected by torrential rains in western Japanese prefectures of Ehime, Hiroshima and Okayama.

Dec. 23 -- Emperor Akihito turns 85.

Jan. 7, 2019 -- Marks the 30th anniversary of accession.

Feb. 24 -- The government holds ceremony marking the emperor's 30 years on throne.