Prajadhipok was born on 8 November 1893 in
Bangkok, Siam (now Thailand) to King
Chulalongkorn and Queen
Saovabha Phongsri. Prince Prajadhipok was the youngest of nine children born to the couple. Overall he was the king's second-youngest child (of a total of 77), and the 33rd and youngest of Chulalongkorn's sons. Unlikely to succeed to the throne, Prince Prajadhipok chose to pursue a military career. Like many of the king's children, he was sent abroad to study, going to
Eton College in 1906, then to the
Woolwich Military Academy from which he graduated in 1913. He received a commission in the
Royal Horse Artillery in the
British Army based in
Aldershot. In 1910 Chulalongkorn died and was succeeded by Prajadhipok's older brother (also a son of Queen Saovabha),
Crown Prince Vajiravudh, who became King Rama VI. Prince Prajadhipok was by then commissioned in both the British Army and the Royal Siamese Army. With the outbreak of the
First World War and the declaration of Siamese neutrality, King
Vajiravudh ordered his younger brother to resign his British commission and return to Siam immediately, a great embarrassment to the prince, who wanted to serve with his men on the Western front. Once home, Prajadhipok became a high-ranking military official in Siam. In 1917 he was ordained temporarily as a monk, as was customary for most Buddhist Siamese men. In August 1918 Prince Prajadhipok married his childhood friend and cousin
Rambai Barni, a descendant of King Mongkut (Prajadhipok's grandfather) and his Royal Consort
Piam. They were married at
Sukhothai Palace which was a wedding gift to the couple from Queen
Saovabha. After the war in Europe ended, he attended the
École Superieure de Guerre in France, returning to Siam to the Siamese military. During this time, he was granted the additional title
Krom Luang Sukhothai (Prince of
Sukhothai). Prajadhipok lived a generally quiet life with his wife at their residence,
Sukhothai Palace, next to the
Chao Phraya River. The couple had no children. Prajadhipok soon found himself rising rapidly in succession to the throne, as his brothers all died within a relatively short period. In 1925, King
Vajiravudh himself died at the age of 44. Prajadhipok became absolute monarch at only thirty-two. He was crowned King of Siam on 25 February 1926. ==Last absolute monarch==