It’s hard to think of a symbol of COVID-19 more fraught than the N95 respirator. The mask fits tightly around the face and is capable of filtering 95% of airborne particles, such as viruses, from the air, which other protective equipment (such as surgical masks) can’t do. It’s a life-saving device that is now in dangerously short supply. As such, it has come to represent the extreme challenges of the global response to COVID-19.

How did a flimsy polymer cup become the most significant health device of the 21st century? It all started in 1910 with a little-known doctor who wanted to save the world from one of the worst diseases ever known.

Going back even further—long before we understood that bacteria and viruses could float through the air and make us sick—people improvised masks to cover their faces, says Christos Lynteris. Lynteris is a senior lecturer at the Department of Social Anthropology at the University of St. Andrews, who is an expert in medical mask history.

He points to Renaissance-era paintings where people cover their noses with handkerchiefs to avoid illness. There are even paintings from Marseilles in 1720, which was the epicenter of the bubonic plague, that show gravediggers and people handling bodies with cloth around their faces, even though the plague was spread by the bites of fleas that traveled on rats.

“It was not meant to be against the contagion,” says Lynteris of the practice. “The reason these people were wearing cloth around their mouths and noses was, at the time, they generally believed diseases like the plague were miasma, or gases emanating from the ground. It wasn’t to protect you from another person, they believed plague was in the atmosphere—corrupt air.”