The Black Death was a disease that attacked the Western world in different centuries. The first outbreak, also the most violent, reached Europe in 1346. Still, the stereotypical doctor costume was used until the 17th century.
The plague doctors were not traditionally trained professionals like experienced doctors or surgeons. In many cases, they were second-rate doctors who had been unable to establish themselves or young doctors trying to make themselves a name.
Because the city paid their salary, they took care of all citizens, both rich and poor, no matter what city they were from.
The beak-shaped mask, the most distinctive feature of the suit, was a testament to the ingenuity of the plague doctors. In that beak, about 15 centimeters long, they kept spices and aromatic herbs. This innovative design protected the doctors from inhaling the 'pestilential miasma' that reached them from the sick through the air, preventing them from contagion and the smell of the dead.