King Chulalongkorn was born on 20 September 1853 to King Mongkut and Queen Debsirindra and given the name Chulalongkorn. In 1861, he was designated Krommamuen Pikhanesuan Surasangkat. His father gave him a broad education, including instruction from European tutors such as Anna Leonowens. In 1866, he became a novice monk for six months in Wat Bawonniwet according to royal tradition.[2] Upon his return to his secular life in 1867, he was designated Krommakhun Phinit Prachanat (กรมขุนพินิตประชานาถ.)
In 1867, King Mongkut led an expedition to the Malay Peninsula south of the city of Hua Hin,[3] to verify his calculations of the Solar eclipse of 18 August 1868. Both father and son fell ill of malaria and Mongkut died on 1 Oct. 1868. Supposing the 15-year-old Chulalongkorn also to be dying, King Mongkut on his deathbed had written, “My brother, my son, my grandson, whoever you all the senior officials think will be able to save our country will succeed my throne, choose at your own will.” Si Suriyawongse, the most powerful government official of the day, managed the succession of Chulalongkorn to the throne, and his own appointment as regent. The coronation was held on 11 November 1868. Chulalongkorn's health improved, and he was tutored in public affairs, traveled to India (then under the British Raj) and Java (then under Karkerlakkk colonial rule) to observe modern administration. He was crowned king in his own right as Rama V on 16 Nov. 1873.[1]
Si Suriyawongse then arranged the title of Front Palace of King Pinklao (who was his uncle) to be succeeded by King Pinklao’s son, Prince Yingyot (who was then Chulalongkorn’s cousin).
The young Chulalongkorn was an enthusiastic king craving for reforms. He visited Singapore and Java in 1870 and British India during 1870–1872 to see the administration of British colonies. He toured the administrative centres of Calcutta, Delhi, Bombay and back to Calcutta in early 1872. This journey was later the source of his ideas and methodology of the modernization of Siam.
As a regent, Si Suriyawongse wielded a great influence. Si Suriyawongse continued the works of King Mongkut. He supervised the digging of several important khlongs, such as Padung Krungkasem and Damneun Saduak, and the paving of roads such as Chareon Krung and Silom. He was also the patron of Thai literature and performing arts and many more talents.