Originally posted by the Voice of America. Voice of America content is produced by the Voice of America, a United States federal government-sponsored entity, and is in the public domain. In Photos: The Reign of Thai King Bhumibol Adulyadej by VOA News King Bhumibol Adulyadej was the world's longest-reigning and the country's revered monarch. Bhumibol, a constitutional monarch with no formal political role, was widely regarded as Thailand's unifying figure.