Phra Bat Somdet Phra Poraminthra Maha Chulalongkorn Phra Chunla Chom Klao Chao Yu Hua (Thai: พระบาทสมเด็จพระปรมินทรมหาจุฬาลงกรณ์ พระจุลจอมเกล้าเจ้าอยู่หัว), or Rama V (20 September 1853 – 23 October 1910) was the fifth monarch of Siam under the House of Chakri. He was known to the Siamese of his time as Phra Phuttha Chao Luang (พระพุทธเจ้าหลวง – The Royal Buddha). He is considered one of the greatest kings of Siam. His reign was characterized by the modernization of Siam, immense government and social reforms, and territorial cessions to the British Empire and French Indochina. As Siam was threatened by Western expansionism, Chulalongkorn, through his policies and acts, managed to save Siam from being colonized. All his reforms were dedicated to Siam’s insurance of survival in the midst of Western colonialism, so that Chulalongkorn earned the epithet Phra Piya Maharat (พระปิยมหาราช – The Great Beloved King).
The Chakri Dynasty (Thai: ราชวงศ์จักรี; RTGS: Ratchawong Chakkri Pronunciation) is the current ruling royal house of the Kingdom of Thailand, the Head of the house is the King of Thailand. The dynasty has ruled Thailand since the founding of the Ratthanakosin era and the city of Bangkok in 1782 following the end of King Taksin of Thonburi's reign, when the capital of Siam shifted to Bangkok. The Royal house was founded by King Buddha Yodfa Chulaloke, an Ayutthayan military leader.
Prior to the founding of the dynasty, King Buddha Yodfa Chulaloke (Rama I), held the title of Chao Pharaya Chakri for over ten years. This title was held by the greatest warlords of Ayuthaya and was meant to reflect the prowess of the holder on the battlefield. In the founding of the dynasty King Rama I himself chose both name and emblem for the dynasty. The Chakri which provides both name and emblem to the house of Chakri, is composed of the discus (Chakra) and the trident (Trisula, sometimes shortened to "Tri" in Thai language), the celestial weapon of the God Narayana (an Avatar of Vishnu) of whom the Siamese king is seen as a personification. The coined name Chakri thus denotes the transcending force of divine strength and stability upon the physical realm. (Cf. Chakravartin.) The current Head of the Dynasty is King Bhumibol Adulyadej since 1946, the Heir Apparent to the headship is Crown Prince Maha Vajiralongkorn. The House's dynastic seat is the Grand Palace in Bangkok.