Crown princes of Thailand

Vajiralongkorn (born 28 July 1952), also known by his regnal name Rama X, is King of Thailand, reigning since 2016. He is the 10th monarch of the Chakri dynasty, the reigning dynasty of Thailand since 1782.

Vajiravudh (1 January 188126 November 1925) was the sixth king of Siam from the Chakri dynasty, titled Rama VI. He reigned from 1910 until his death in 1925. King Vajiravudh is best known for his efforts to create and promote Siamese nationalism. His reign was characterized by Siam's further Westernization, minimal participation in World War I, and lavish spending on arts and culture. He had keen interests in Siamese history, archaeology, and literature, as well as economics, politics and world affairs, and founded the country's first university, Chulalongkorn University.

Maha Vajirunhis, Crown Prince of Siam (; ; 27 June 1878 – 4 January 1895) was the first Crown Prince of the Chakri dynasty. He was the first son of King Chulalongkorn and Queen Savang Vadhana together, who were half-siblings.