His death means Britain’s Queen Elizabeth now becomes the world’s longest living reigning monarch.
The loss of the Thai monarch, whose reign began back in 1946, could have major implications for the political and economic landscape in Thailand.
Since he first came to power, Thailand has switched between military-backed authoritarianism mixed with short periods of semi-democracy.
Pushed in tourism marketing as the land of smiles, Thailand has now become the land of mourning.
The King’s only son Maha Vajiralongkorn, now 64, was appointed by his father as the crown prince in 1972. He is, however, seen by many of his people as something of a playboy, jet-setting around the world.
The military coup which took place two years ago is believed by many analysts to have been a strategic move to gain more power before the ascension of the new King.
Thailand is now expected to enter a lengthy period of official mourning.
Previously when members of the Thai royal family have died, there has followed a period in which the body has lain in state and there has also been 100 days of mourning, followed by a six-day funeral ceremony.
Whether those arrangements will be the same this time round remains to be seen. This is because Thailand has an incredibly strict law which means it is a crime to insult any members of the royal family. In practice, this makes it very difficult even to talk about them because of fear of recrimination.
The Thai prime minister General Prayuth is reported as saying that the crown prince does not want to be proclaimed king immediately as he wants time to properly mourn his father.
A one-year period of mourning has now been announced for public officials and all public celebrations have been postponed for at least 30 days.
Tourists are being advised to dress more respectfully and to bear in mind the situation while out in public.
The Foreign and Commonwealth Office has not yet changed its official advice, but tourists are being told to be careful when in public places. While those in the beach resorts such as Phuket and Koh Samui are unlikely to notice a change, the situation in Bangkok could quickly become more volatile.