Phra Bat Somdet Phra Poramintharamaha Chulalongkorn Phra Chunla Chom Klao Chao Yu Hua, or Rama V (20 September 1853 – 23 October 1910) is the fifth monarch of Siam under the House of Chakri.

He is known to the Siamese of his time as Phra Phuttha Chao Luang (The Royal Buddha).

He is considered one of the greatest kings of Siam.

His reign is characterized by the modernization of Siam, immense government and social reforms, and territorial cessions to the British Empire and French Indochina.

As Siam is threatened by Western expansionism, Chulalongkorn, through his policies and acts, manages to save Siam from being colonized.

All his reforms are dedicated to Siam’s insurance of survival in the midst of Western colonialism, so that Chulalongkorn earns the epithet Phra Piya Maharat (The Great Beloved King).