El Cid

Skylitzes.jpg

From the manuscript known as "Madrid Skylitzes" made by John Skylitzes in the 1100s. The first known example of separating conjoined twins happened in the Byzantium in the 900s. One of the conjoined twins died, so the surgeons in Constantinople decided to remove the body of the dead one. The result was partly successful, as the surviving twin lived three days before dying, a result so impressive that it was mentioned a century and half later by historians. The next case of separating conjoined twins would not occur until 1689 in Germany.

Source: http://www.medievalists.net/2014/01/the-case-of-conjoined-twins-in-10th-century-byzantium/