Lazarus is the poor man at the gate of the rich man in Christ's parable related in Luke. (Luke 16:19-31)
The Order of Saint Lazarus was founded in the 12th Century to provide nursing for lepers, taking Lazarus as its patron. The knights of the order were lepers, and besides helping their fellow sufferers, they carried out military duties. They founded a hospital for lepers near the northern wall of Jerusalem.