Thailand has been ruled since 1782 by the Chakri dynasty. All kings of this dynasty are known as Rama.
Before coming to the throne, Rama X was known as Vajiralongkorn. Similarly his father, Rama IX, was known as Bhumibol Adulyadej.
As stated elsewhere on my Kings & Queens: Modern Non–European page, the King of Siam featured in the musical The King and I was Rama IV (a.k.a. Mongkut the Great), who ruled from 1858 to 1868.
© Haydn Thompson 2021