Otzi was to be killed by an arrow to the back, but he became infamous after being found quite the same as when he died, 3,300 years after his assassination. The cold and dry environment 10,500 feet up in the Otzal mountain preserved his body to an unnatural degree; so much so that the hikers who found him assumed he was a recent victim. But discovery was only the first surprise Otzi would carry.

On this day, September 19, in 1991, a German group hiking in the Alps stumbled on to what turned out to be a historic discovery: a remarkably preserved body — not just bones, but also soft tissue, clothing and even stomach contents — from the prehistoric period 3,300 years ago.

Otzi overturned a number of assumptions about his people. For one thing, he carried a shaped axe that archaeologists thought was not made for another 500 years. His clothing, also remarkable in its constructions, was made from stitched fur with a layer of woven grasses over it for water repelling. The complexity of its construction further led scientists to the surprising conclusion that the Chalcolithic Europeans were more advanced than previously assumed.