An excellent read regarding the various transformations of the order originally known as the Knights Hospitaller. They were originally formed under papal order to serve as healers and to build hospitals for Christian pilgrims. Soon they become both a fighting force and a major source of income yet fell on hard times as kingdoms rose and fell and the Christian denominations were no longer cohesive. They do still exist today and serve in a similar healing capacity, only now (2019) they serve victims of war and rampaging disease.
Interesting note: here is where you will find the original purpose of the Maltese Falcon! ( )