Ananda Mahidol was born September 20, 1925 in Heidelberg, Germany, where his parents, Mahidol Adulyadej Prince of Songkhla (son of king Chulalongkorn) and Somdej Phra Sri Nakarindhara were studying at that time. He spent his youth mostly in Switzerland after his father died in 1929.
On March 2, 1935 he was elected by the Thai parliament and government to succeed his uncle, king Prajadhipok (Rama VII), who abdicated earlier due to political quarrels with the new republican government as well as health problems. The republican government worried about the king influencing politics too much and therefore chose the young Ananda Mahidol, only 9 years old at that time and attending school in Lausanne, Switzerland.
At age 13 he visited Thailand for the first time, together with his mother and his brother Bhumibol Adulyadej, but only after the end of World War II did he return, in December 1945, for a second visit. He quickly won the hearts of his people, however on June 9, 1946, he was found shot dead in his sleeping room, only four days before he was scheduled to return to Switzerland to continue his education.
His death is still a mystery. The official version is that he shot himself accidentally while cleaning his gun, but suicide or even murder is speculated about.
His brother Bhumibol Adulyadej succeeded him. Ananda Mahidol was never crowned as king, but his brother posthumously gave him the full royal title of the nine-fold umbrella.