Conjoined twins in 10th century Byzantium

From Medievalists.net:

Leo the Deacon, writing in his History, provides his firsthand observation of seeing the conjoined twins, sometime during the mid-940s:

At this time male twins, who came from the region of Cappadocia, were wandering through many parts of the Roman Empire; I myself, who am writing these lines, have often seen them in Asia, a monstrous and novel wonder. For the various parts of their bodies were whole and complete, but their sides were attached from the armpit to the hip, uniting their bodies and combining them into one. And with the adjacent arms they embraced each other’s necks, and in the others carried staffs, on which they supported themselves as they walked. They were thirty years old and well developed physically, appearing youthful and vigorous. On long journeys they used to ride on a mule, sitting sideways on the saddle in the female fashion, and they had indescribably sweet and good dispositions. But enough about this.

...During the reign of Constantine VII (944-59) the twins returned to Constantinople. Theophanes Continuatus explains what happens next:

When one of the twins died skilled doctors separated them cleverly at the line of connection with the hope of saving the surviving one but after living three days he died also. This is the earliest known attempt to surgically separate conjoined twins, and the fact that the second person survived for a even a few days showed that it was at least partly successful. There would not be another case of conjoined twins being separated until the year 1689.