File photo taken in 1976 shows Prince Rainier III of Monaco, Princess Grace, Princess Stephanie, Prince Albert and Princess Caroline. (AFP)

Picture taken 19 April 1956 of Prince Rainier of Monaco with Grace Kelly, Princess Grace, on their wedding day. (AFP)

Prince Rainier III of Monaco has died at 81 after spending weeks in hospital for heart and breathing problems. (Reuters/File)

    PARIS, April 6 (Xinhuanet) -- Prince Rainier III of Monaco died at age 81 on Wednesday after a battle with heart, kidney and breathing problems, Monaco's royal palace announced.

    The prince, who ruled the tiny Mediterranean principality since 1949, passed away at 06:35 local time (0435 GMT), the palace said in a statement.

    He was Europe's longest reigning monarch.

    Rainier will be succeeded by 47-year-old Prince Albert, who took over his father's royal duties last week after Rainier's condition suddenly turned worse nearly two weeks ago.

    Rainier suffered recurring health problems and had several operations in recent years before he was hospitalized on March 7 with a lung infection. Enditem