Bhumibol Adulyadej, conferred with the title King Bhumibol the Great in 1987, was the ninth monarch of Thailand from the Chakri Dynasty as Rama IX. Having reigned since 9 June 1946, he was, at the time of his death, the world's longest-serving head of state and the longest-reigning monarch in Thai history, serving for 70 years, 126 days. During his reign, he was served by a total of 30 prime ministers beginning with Pridi Banomyong and ending with Prayut Chan-o-cha. In 1957, a military coup overthrew the government of Field Marshal Plaek Phibunsongkhram with allegations of lèse-majesté, which is an offense against the dignity of the monarch, punishable under Thai law. This began a new and long-lasting relationship between the monarch and military. Although Bhumibol did invite public criticism in a 2005 speech, the lèse majesté laws have not been revoked by the Thai parliament. Forbes estimated Bhumibol's fortune—including property and investments managed by the Crown Property Bureau, a unique body that is neither private nor government-owned—to be US$30 billion in 2010, and he was the head of the magazine's list of the "world's richest royals" from 2008 to 2013. In May 2014, Bhumibol's wealth was once again listed as US$30 billion. Officially the assets managed by the CPB are owned by the crown as an institution, not Bhumibol Adulyadej as an individual. After 2006, Bhumibol suffered declining health and spent extended periods at Siriraj Hospital, where he died on 13 October 2016. He was generally highly revered by the people in Thailand – many even saw him as close to divine. Notable political activists and Thai citizens who criticized the king or the institution of monarchy were often forced to exile the country or suffered frequent imprisonments. His successor Vajiralongkorn does not share the popularity of his father, leading to concerns that the Thai monarchy will lose prestige and influence under the latter's reign.

https://en.wikipedia.org/wiki/Bhumibol_Adulyadej