How the original Siamese twins had 21 children by two sisters

The walls in Chang and Eng Bunker’s bedroom would have had some tales to tell, if walls could talk. Their marital bed was built for four — brothers Chang and Eng in the middle and their wives on either side. Between them, they conceived some 21 children in that bed.
For Chang and Eng were the original Siamese Twins, conjoined siblings who provided the name for all who suffer this accident of birth.dailymail.co.uk
As a new biography reveals, the pair triumphed over extraordinary odds and appalling prejudice in 19th-century America and Britain. Brought to the West to be exhibited as freaks and probed by doctors, the enterprising Bunkers eventually became rich Southern gentlemen and plantation owners.
But, says U.S. academic Joseph Orser in The Lives of Chang and Eng, the pair were never allowed to forget that many considered them ‘monsters’ whose sexual urges and desire to pursue a normal family life were unnatural, even devilish, abominations.
Born in 1811 in a fishing village 60 miles from Bangkok, the twins really had their roots more in China than in Siam, later renamed Thailand. Their father was a Chinese fisherman and their 35-year-old mother was half-Chinese, half-Malay.
The two midwives who helped at the birth recoiled in superstitious horror at the thick ligament connecting the babies just above their waists. The twins’ mother probably saved their lives by untwisting the ligament — which had been connected to a single umbilical cord — and moving the babies so they lay staring into each other’s eyes. She named them In and Jun (anglicised to Eng and Chang). Chang — on the left — was always slightly shorter and the upper half of his body arched away from his brother.
Their mother encouraged the boys to exercise, stretching their connecting ligament so that it gradually grew to more than five inches — enough for them to run, swim and handle a boat. Crucially, they were able to bow 18 times, as custom dictated, when they were presented to the king of Siam, Rama III.
Their life, helping their family to sell preserved ducks’ eggs, might have passed in obscurity had they not been spotted by a British merchant when they were adolescents.
Robert Hunter at first thought the twins were ‘some strange animal’ when he saw them swimming in a river. But he recognised their commercial potential and easily persuaded their impoverished family that the twins should accompany him back to the West and be exhibited as a public curiosity. They agreed but the king, who wanted to show them off at court, was reluctant.