Phra Bat Somdet Phra Poramenthra Maha Mongkut Phra Chom Klao Chao Yu Hua or Rama IV, known in English-speaking countries as King Mongkut , was the fourth monarch of Siam (Thailand) under the House of Chakri, He was one of the most revered monarchs of the country.
Mongkut was also known for his appointing his brother, Prince Chutamani, as Second King, crowned in 1851 as King Pinklao. Mongkut himself assured the country that Pinklao should be respected with equal honor to himself (as King Naresuan had done with his brother Ekathotsarot in 1583.) Mongkut's reign was also the time when the power of the House of Bunnag reached its zenith and became the most powerful noble family of Siam.