Medieval nurses were women who attended to the more basic needs of the ill in hospitals. Many joined monastic orders, but there were secular nursing orders as well, especially during the Plague. As the disease spread women from all socio-economic groups came forward to care for the sick. Noble-born women who became nurses of the poor or sick, were considered "nursing saints."
In premodern times, nuns and the military often provided nursing services. The religious and military roots of modern nursing remain in evidence today. For example, in Britain, senior female nurses are known as "Sisters".
Florence Nightingale is regarded as the founder of modern nursing, which flourished in response to the World Wars. Camillus I believe would prefer to be remembered for founding the Camillans, although he is the patron saint of nurses, and established a hospital in Rome in the 1500s.