The Garamantian civilization of ancient North Africa survived and thrived in the Sahara Desert from 1,100 BCE to 600 CE. Three newly discovered skull reveal that the Garamantians practiced medicine. Unfortunately, it involved making tiny holes in people's skulls.
This practice, known as trepanning, is quite possibly the oldest medical procedure known to humankind. Evidence of drilling and cutting at skulls dates all the way back to ancient Morocco 13,000 years ago. The Garamantian skulls - you can see one of them up top - showed evidence of holes and depressions that archaeologists believe were made during these procedures. We can also see renewed growth of the bone around these incisions, which indicates the patients survived the procedure and went onto at least a somewhat successful recovery.
Although the medical benefits of trepanning are murky at best, it does appear that the ancient surgeons knew a little something about what they were doing. The holes in the skulls were carefully positioned to sidestep the sensitive cranial sutures that, if damaged, would have caused intense pain to the patients. Indeed, that's a major reason why the archaeologists are fairly certain that this was intended as a form of beneficial surgery, as opposed to some sort of torture.
We don't know exactly why the Garamantians performed trepanning. Some groups in North Africa continue the practice today to relieve severe headaches brought on by disease or injury. Another ancient Saharan skull showed signs of preexisting cranial trauma, which might suggest the trepanning procedure was done in response to this injury.