Mystras or Mistras (Greek: Μυστρᾶς/Μιστρᾶς),[2] also known in the Chronicle of the Morea as Myzethras or Myzithras (Μυζηθρᾶς), is a fortified town and a former municipality in Laconia, Peloponnese, Greece.

Taygetus, above ancient Sparta, and below a Frankish castle,[3] it served as the capital of the Byzantine Despotate of the Morea in the 14th and 15th centuries, experiencing a period of prosperity and cultural flowering during the Palaeologan Renaissance, including the teachings of Gemistos Plethon.

The final main building follows the form of the Tekfur saray in Constantinople/Istanbul: three stories with the topmost devoted to a large audience hall, and the lower levels used for apartments and storerooms.

[3] In late 1248, William II of Villehardouin, ruler of the Frankish Principality of Achaea, captured Monemvasia, the last remaining Byzantine outpost on the Morea.

[2][8] In September 1259, William of Villehardouin was defeated and captured, along with many of his nobles, at the Battle of Pelagonia, by the forces of the Nicaean emperor Michael VIII Palaiologos.

At this point, the emperor concluded an agreement with the captive prince: William and his men would be set free in exchange for an oath of fealty, and for the cession of Monemvasia, Grand Magne, and Mystras.

[2] Almost immediately on his return to the Morea, William of Villehardouin renounced his oath to the emperor, and warfare broke out between Byzantines and Franks.

[10] The insecurity engendered by the raids and counter-raids caused the inhabitants of Lacedaemon to abandon their exposed city and settle at Mystras, in a new town built under the shadow of the fortress.

For the larger portion of his reign, Manuel maintained peaceful relations with his Latin neighbors and secured a long period of prosperity for the area.

[11] This was the city's golden age; according to the Oxford Dictionary of Byzantium, Mystras "witnessed a remarkable cultural renaissance, including the teaching of Plethon, and attracted artists and architects of the highest quality"[2] Mystras was the last centre of Byzantine learning and culture; the famous Neoplatonist philosopher Gemistos Plethon lived there until he died in 1452.

He and other scholars based in Mystras influenced the Italian Renaissance, especially after he accompanied the emperor John VIII Palaiologos to Florence in 1439.

The majority of the most important churches are still standing, including St. Demetrios, the Hagia Sophia, St. George, and the Monastery of Peribleptos.