Chang Bunker and Eng Bunker (May 11, 1811 – January 17, 1874) were Siamese-American conjoined twin brothers whose fame propelled the expression "Siamese twins" to become synonymous for conjoined twins in general. They were widely exhibited as curiosities and were "two of the nineteenth century's most studied human beings".
The brothers were born in Siam (now known as Thailand) to a family of Chinese descent and were brought to the United States in 1829. They became known to American and European audiences in "freak shows". Newspapers and the public were initially sympathetic to them, and within three years, the brothers left the control of their managers, who they thought were cheating them, and toured on their own.