According to most historians, the modern hospital as we know it today traces its origins to the eastern part of the Roman Empire, the part that after the final partition of the Empire by Theodosius the Great (AD395) became the Byzantine Empire.
Research into the history of the hospitals has been difficult, because only scattered ruins of former buildings survive and relevant manuscripts have been lost. There is substantial agreement, however, that no institutions resembling hospitals existed in the ancient world, even though the Romans had some facilities serving soldiers, servants, slaves, injured gladiators, and the very poor – so-called proto-hospitals, more often places to die rather than to be cured.
Only with the advent of Christianity did it become the duty of every believer to practice charity. Already by AD 250 the church in Rome had made arrangements to distribute food to the poor. After the conversion of Constantine the Great (reigned 306–337) Christianity became the state religion, poverty increased because of major demographic changes, and more permanent institutions were developed.
In the East these took the form of xenones or xenodocheia, meaning for strangers. They provided food, shelter, and clothing for the poor, also pack animals for travelers. The first permanent such institutions were founded in the earlier part of the fourth century by Bishops Leontios in Antioch (344-358) and Eustathios in Sebasteia (c.357-377). They were generally attached to churches or monasteries, run by monks and with no doctors involved.
The first institution with permanent buildings resembling a hospital is said to have been founded around 372- 379 by Saint Basil, bishop of Caesarea in Cappadocia. It had doctors in attendance, also a leprosarium that would sometimes also admit patients with other illnesses.
Between 398-404 John Chrysostom, bishop of Constantinople, developed a similar institution, having physicians but still offering food and shelter to the poor and strangers.