Prince Purachatra Jayakara, the Prince of Kamphaengphet (23 January 1881 - 14 September 1936) was a Prince of Siam (later Thailand), the 35th son of King Chulalongkorn (Rama V the Great). He had 2 spouses and 5 consorts, with whom he had 12 children (4 sons and 8 daughters), and founded the House of Chatrajaya. He was often called the Father of the Thai radio and the Father of the Thai railways, due to his contributions in both fields.
He received the education in Suankularb Wittayalai School, then in Harrow School, School of Engineering at Trinity Canbridge, University of Cambridge, and engineering at Chatham. Also he attended studying in France and Netherlands in the School of engineering of digging dam-canals. He came back to Thailand in 1904, and worked as the military engineer, and officer of the Siamese Royal Army for 17 years. He developed the Siamese Department of Engineering militaries in his knowledge he got from the western. Later he retired himself and moved to Singapore with his family in 1933. He resided there until his death on 14 September 1936, at the age of 55.