Prince Savang Vatthana was born on 13 November 1907 at the Royal Palace of Luang Prabang, the son of King Sisavang Vong and Queen Kham-Oun I. He was the second of five children along with Princess Khampheng, Princess Sammathi, Prince Sayasack, and Prince Souphantharangsri. He was also a distant cousin of Prince Souvanna Phouma and Prince Souphanouvong. At the age of 10, Prince Savang was sent to study in France. He attended a lycée in Montpellier and obtained a degree from École Libre des Sciences Politiques (now called Sciences Po) in Paris, where French diplomats were trained. The young heir continued his studies in France, and after a decade overseas, he could no longer speak Lao. Upon his return, he had to be instructed by a palace functionary for years.

On 7 August 1930, he married Queen Khamphoui and they had five children, Crown Prince Vong Savang, Prince Sisavang Savang, Prince Sauryavong Savang, Princess Savivanh Savang, and Princess Thala Savang. The family played tennis together, and liked to attend major tournaments on their travels abroad. The prince was also a devout Buddhist and became an authority on the sangkha, and would later take his role as protector of the state religion seriously.

In 1951, he served as Prime Minister, and when his father became ill on 20 August 1959, he was named Regent. On 29 October 1959, he informally acceded upon the death of his father. He was, however, never officially crowned and anointed king, deferring his coronation until the cessation of civil war. During his reign, Savang Vatthana visited many countries on diplomatic missions. In March 1963, he toured 13 countries, including the United States, where he stopped at Washington, D.C., to meet with President Kennedy. It was the second stop on a tour of 13 of the nations signatory to the Geneva Pact that guaranteed the “neutrality” of the Kingdom of Laos. The first stop had been Moscow, and the Russians showered gifts, including the GAZ Chaika limousines. He was also accompanied by his Prime Minister, Souvanna Phouma.

In 1961, a majority of the National Assembly had already voted Boun Oum into power and King Sisavang Vatthana left Luang Prabang, visiting the capital to give the new government his blessing. But he wanted the Three Princes to form a coalition government, which happened in 1962 but then the coalition government collapsed.

In 1964 series of coups and counter coups resulted in the final alignment of the Pathet Lao on one side with the neutralist and right wing factions on the other. From this point the Pathet Lao refused to join any offers of coalition or national elections and the Laotian Civil War began.

On 23 August 1975, Pathet Lao forces entered Vientiane, the last city to be captured. The Phouma Government became effectively powerless for the next few months. On 2 December, Vatthana was forced to abdicate the throne by the Pathet Lao, abolishing the 600-year-old monarchy, and was appointed to the meaningless position of “Supreme Advisor to the President”. He refused to leave the country and in 1976 he surrendered the royal palace to the Lao Government, which turned it into a museum, and moved to a nearby private residence where he was later placed under house arrest. In March 1977, fearing Vatthana might escape to lead a resistance, the Communist authorities arrested him along with the Queen, Crown Prince Vong Savang, Prince Sisavang, and his brothers Princes Souphantharangsri and Thongsouk and sent them to the northern province of Viengxai. He was transported to Xam Neua and imprisoned in “Camp Number One,” which held high-ranking officials from the former government. During his time in the camp, he and other members of the royal family were allowed to move freely around their compounds during the day, and were often visited by members of the politburo, including Sopuhanouvong himself. Vatthana was the oldest prisoner in the camp and turned 70 during the earlier months of his imprisonment, whereas the average age of prisoners was around 55.

In 1978, the government reported that Vatthana, Queen Khamphoui, and Crown Prince Vong Savang had died from malaria. The World Press Review reported that they had suffered from the effects of forced labor and starvation. More recent accounts suggest that the King died in mid-March 1980. However, according to Kaysone Phomvihane, Vatthana died in 1984, at the age of 77. Following the deaths of Vatthana and the Crown Prince, the King’s youngest son, Sauryavong Savang, became the head of the Laotian royal family, acting as regent for his nephew Crown Prince, Soulivong Savang, until the regent died in Paris in 2018.