On the afternoon of May 6, in a darkened lecture hall, 75 midwives, obstetrical nurses, doctors, and students studied a PowerPoint slide showing an almost 500-year-old woodcut. The image from 1510, an illustration for the much older book Lives of the Twelve Caesars by Suetonius, shows an early cesarean section. The mother is dead. She lies naked and sliced open as a midwife lifts the baby from her gaping womb. Standing behind the body is a surgeon, his foot-long scalpel held aloft, at the top of the image.
“It’s always been about the sword,” quipped cesarean specialist Eugene Declercq, a guest professor from the Boston University School for Public Health. “Today we have extraordinary levels of interventions [into deliveries], but the mothers aren’t complaining. It’s as though someone told women, ‘If the baby is healthy, don’t complain.’”
... led me to track down the image, which purportedly depicts the birth of Julius Caesar. (I think it's the same one; the page it resides on at the National Library of Medicine says it's from 1506). This pushes back the mention in the OED (which we mentioned the first time we yakked about this), which suggests it is first mentioned in 1540 or thereabouts ...
I should probably mention that I have been repeatedly spelling this word as Caesarian, as opposed to Caesarean (or Cesarean), for no particular reason, other than I'm not sure why the 'e' is to be preferred to the 'i', other than, perhaps, to distinguish the operation from 'party members' of Caesar.