Answer
Vajiralongkorn is the only son of King Bhumibol Adulyadej, who reigned over Thailand for seven decades. Bhumibol was highly revered and considered the father of the nation, known for his dedication to improving the lives of his subjects and his extensive development projects. His reign was marked by social and economic progress, and he played a crucial role in maintaining Thailand's stability amidst political turmoil and regional conflicts.