Around 5,300 years ago, a short, thin, middle-aged man ate his last meal—red deer and grains. Life was tough for the 45-year-old. He suffered from joint pain, possibly from herding sheep on the high mountain peaks in the Italian Alps. His teeth were rapidly decaying. He was infected by parasitic worms, and he possibly had Lyme disease.

Still, in spite of all these problems, the 5-foot-3-inch, heavily-tattooed man persevered. And it was no easy feat to survive. Europeans, still transitioning from a hunter-gatherer society, had just began to cultivate crops.

We were at the very beginning of our history, before the great ancient civilizations. To put just how long ago he lived in perspective, it was approximately 800 years before the Great Pyramid of Giza was constructed. Stonehenge wouldn’t be built for another 600 years.

During the final 33 hours of his life, the man—now known as Ötzi the Iceman—trekked great distances over the rugged, mountainous terrain on the border of Austria and Italy. He climbed from the frigid cold peaks, armed with a copper-bladed axe, down to his village.

What happened next is still a mystery, but we do know that he got involved in a battle. He was pierced with an arrow in his shoulder and subsequently suffered from a head blow—injuries that would end his life.

For thousands of years, his dead body would lay entombed in those glaciers, mummified and preserved in ice, while societies rose and fell around him. It wasn’t until 1991 when two hikers happened to stumble upon his corpse by chance. Unintentionally, they had discovered the oldest known mummy in Europe.

“[His body alone has] contributed greatly to the knowledge of the lifestyle of Neolithic humankind,” writes researchers in a study published in the journal Quaternary Science Reviews.

Redditors agree:

His body has provided us a window to a dead world—we were able to determine his migration patterns, diet, fashion, and genetic history, reconstructing his last days on Earth.

“Often one finds nothing else but some broken tools and pots, and if one is lucky also some bones of animals and humans. Most of the knowledge about man of prehistoric times (i.e. before written record appeared some 5000 years ago) comes from studying burial sites,” writes researcher Walter Kutschera in his study on the iceman.

More recently, researchers were able to sequence the genome of Helicobacter pylori, bacteria that co-evolved to live in the human stomach, by taking samples from the mummy’s ancient gut. They published the results earlier this week in the journal Science.

H. pylori lives in the stomach of around half of the world’s population, colonizing the human gut for around 100,000 years. Different strains are associated with different populations.

Since Ötzi’s DNA is tied to modern-day Sardinians, scientists expected to find strains that most closely matched modern-day Europeans (who have strains that originated in North Africa and Asia). Intriguingly, his bacterial strain only matches those found in India and South Asia.

“This one genome has put things into wonderful perspective for us, answered this question that we’ve been trying to answer for years. We can say now that the waves of migration that brought these African Helicobacter pylori into Europe had not occurred or at least not occurred in earnest by the time the Ice Man was around,” the study’s co-author, Yoshan Moodley, tells the Scientific American.

Clearly, when it comes to Ötzi, there’s no shortage of discovery. Thousands of years after his death, he still continues to help us understand our origins.