Uparat
Krom Phra Ratchawang Bowon Wichaichan () or Phra Ong Chao Yodyingyot (or Yingyot) (พระองค์เจ้ายอดยิ่งยศ) (6 April 1838 – 28 August 1885) was a Siamese Prince and member of the Chakri Dynasty. He was the eldest son of Viceroy Pinklao and Princess Aim, and thus nephew to King Mongkut (Rama IV). Wichaichan succeeded his father by being appointed the Front Palace and "Viceroy of Siam" in 1868, during the reign of his cousin King Chulalongkorn (Rama V). During his tenure the office of Front Palace was extremely powerful and rivalled that of the monarch's own. Inevitably the two forces clashed in the Front Palace crisis. Wichaichan was defeated and the power of the Front Palace was greatly diminished. After his death in 1885, the last vestiges of the title were abolished in favour of a Crown Prince.