When the Roman Empire had been divided between the two sons of the Emperor Theodosius, Malta and its islands came under the Empire of the East which had its capital in remote Byzantium (modern day Istanbul). Very little is known of Maltese history regarding the four centuries starting from around the year 400 AD. This was the period of the break-up of the old Roman Empire, the time when Vandals and Goths carried all before them in Spain and in North Africa and, indeed, on the Italian mainland, the City of Rome itself was taken.

The Byzantines, however, were more successful in warding off the attacks of the barbarians largely because of their powerful navy. About the middle of the 6th century the lands under Byzantine domination were organized into a series of military provinces or Themes.