The Byzantine and Christian Museum was founded in 1914. From 1930 on it has been housed in the "Ilisia" mansion, which belonged to the Duchess of Placentia and was built in 1848 by the architect Stamatis Kleanthes. It was transformed into a museum by the architect Aristotle Zachos. Today an addition is being made and a large extension with basement and buildings in part above ground. The architectural design is by Manos Perrakis.
The collections of the Byzantine Museum show the course of Greek art from the 4th to the 19th century. They comprise sculptural works, paintings and small works of all sorts. These works represent the artistic production of the Greek area, and other regions both central and peripheral of the Byzantine empire and subsequently of Hellenism on into post-Byzantine times.