The founding of Mystras is associated with the first conquest of Constantinople by the Crusaders of the Fourth Crusade in 1204: the Byzantine Empire was divided, the Peloponnese was granted to the Frankish family of the Villehardouins, who founded the Principality of Achaia, and a few years later in 1249 Prince William II of the Villehardouin family builds the castle of Myzithras at the top of the homonymous hill, in a position crucial for the control of the Evrotas valley. This castle will be the nucleus of the later fortress of Mystras, one of the most important post-Byzantine cities.
In 1259, in the Pelagonia battle, the Frank Prince was captured by the Byzantines. For his release, the Byzantine Emperor demanded as ransom the submission of the castles of Monemvasia, Maine and Myzithras, which were eventually given to him three years later, in 1262. The security provided by the naturally fortified hill of Mystras will cause the movement of the population of Lacedaemonia towards it, which will be the beginning of its development in the most important urban centre of the region.
Today Mystras is a castle city frozen in time. The subsequent interventions are non-existent and the data given to us from the past intact. It is literally a visit to Byzantium.