The 86-year-old King Bhumibol Adulyadej has been the head of state of Thailand for more than six decades. During the country's often-turbulent political history, he has acted as a force for continuity and tradition even when the country has lurched between political crises and military coups.
From 1946, when he acceded to the throne, to the present, Bhumibol has reigned through more than 20 prime ministers, 17 military coups and 17 constitutions and steered the country through the destabilizing effects of the nearby Vietnam War during the 1960s and '70s.
Over the years, the king has intervened periodically in political crises, using his influence to try to defuse situations that threatened to destabilize the country.