Chang and Eng Bunker were not the first conjoined siblings, but they were the original Siamese twins. Actually, although they were born in Siam – Thailand now – they were ethnically Chinese, but that somehow does not have quite the same ring to it. Nor did they have much to do with their homeland. They were discovered by a British businessman and in 1829, at the age of seventeen, were spirited away to the United States by a rapacious American sea captain called Coffin. They never saw Siam or their family again.

Two hundred years later, they would probably not be Siamese twins at all. Today the five and a half inches of cartilage that joined them at the sternum would be severed after birth, while their fused liver, the only organ that they had in common, could be divided too. As it was, they spent their sixty-two years linked together in shared celebrity. When Chang, who had a drink problem and had previously suffered a stroke, died one morning in January 1874, the healthy and abstemious Eng knew that he would also die that day. ‘Then I am going too,’ he told his family, which he did within a few hours.

Coffin said that he hoped Chang and Eng would ‘prove profitable as a curiosity’ and he was right. They started off touring in freak shows in Boston and New York. Then they were carted over the Atlantic in steerage while Coffin stayed in a first-class cabin, eventually spending more