Chang Bunker and Eng Bunker (May 11, 1811–January 17, 1874) were the twin brothers whose condition and birthplace became the basis for the term Siamese twins. They were born in Siam (now Thailand), in the province of Samutsongkram, to a Chinese father (Ti-eye) and a half-Chinese/half-Cham mother (Nok).
The Bunkers were joined at the sternum by a small piece of cartilage. Their livers were fused but independently complete. Although 19th century medicine did not have the means to, modern advances in surgical technology would have easily allowed them to be separated today. In 1829, they were discovered in Siam by British merchant Robert Hunter and exhibited as a curiosity during a world tour. Upon termination of their contract with their discoverer, they successfully went into business for themselves. In 1839, while visiting Wilkesboro, North Carolina with P.T. Barnum, the twins were attracted to the town and settled there, becoming naturalized United States citizens.