Origin and development of hospital in the West was related closely with religions and wars. Before the Medieval Ages, priests or physicians treated their patients mainly in temples, which may be regarded as the earliest type of hospital. The military hospital first appeared in the ancient Rome due to war. During the Medieval Ages, most hospitals were attached to monasteries. The Crusades prompted the development of hospitals and hospices along the route taken by the Crusaders. After the Medieval Ages, as the Protestantism rose, the monastic hospitals suffered a major setback and secular hospitals developed. From the 16th century, hospitals of Europe were spread gradually into North America. During the 18th and 19th centuries, function of hospital in medical treatment, education and research was strengthened gradually. In the 20th century, hospital facilities were matured technically and management of hospital became an important problem to which people devoted themselves to resolve it.