CHANG and ENG BUNKER (May 11, 1811 – January 17, 1874) were the conjoined twin brothers whose condition and birthplace became the basis for the term SIAMESE TWINS.
The Bunker brothers were born on May 11, 1811 in Siam (now Thailand), in the province of Samutsongkram, to a fisherman and his wife. Because of their Chinese heritage (as they were born from a Thai Chinese father and Chinese-Malay mother), they were known as the "Chinese Twins" in Siam. They 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 do so, modern surgical techniques would have easily allowed them to be separated.
In 1829, British merchant Robert Hunter discovered them and paid their family to be exhibited as a curiosity during a world tour. Upon termination of their contract with their discoverer, the brothers successfully went into business for themselves. In 1839, while visiting Wilkesboro, North Carolina, the twins were attracted to the area and settled on a 110-acre (0.45 km2) farm in nearby Traphill, becoming naturalized United States citizens.
Determined to start living a normal life as much as possible, the brothers settled on a plantation, bought slaves, and adopted the name "Bunker". On April 13, 1843, they married two sisters: Chang to Adelaide Yates and Eng to Sarah Anne Yates. This made their respective children double first cousins. In addition, because Chang and Eng were identical twins, their children were genetically equivalent to half-siblings, thus making them genetically related in the same manner as half-siblings who are also first cousins.
Their Traphill home is where they shared a bed built for four. Chang and his wife had 10 children; Eng and his wife had 11. In time, the wives squabbled and eventually two separate households were set up just west of Mount Airy, North Carolina in the community of White Plains – the twins would alternate spending three days at each home. During the American Civil War Chang's son Christopher and Eng's son Stephen both fought for the Confederacy. Chang and Eng lost part of their property as a result of the war, and were very bitter in their denunciation of the government in consequence.
After the war, they again resorted to public exhibitions, but were not very successful. They always maintained a high character for integrity and fair dealing, and were much esteemed by their neighbors. The twins died on the same day in January 1874. Chang, who had contracted pneumonia, died rather suddenly in his sleep. Eng awoke to find his brother dead, and called for his wife and children to attend to him. A doctor was summoned to perform an emergency separation, but Eng refused to be separated from his dead brother. He died three hours later. Chang's widow died on April 29, 1892 and Eng's widow died on May 21, 1917.