Siamese twins, also known as conjoined twins, are two individuals who are physically connected to each other at birth. This condition occurs when a single fertilized egg does not fully separate during early development, leading to shared organs or body parts. The extent of their connection can vary widely, from minor attachments to significant shared organs. The term "Siamese twins" originated from the famous conjoined twins Chang and Eng Bunker, who were born in Siam (now Thailand) in 1811. They became well-known in the 19th century and toured as a sideshow act. Today, medical advancements allow for better understanding and management of conjoined twins, including potential surgical separation.