The Castle of Karytaina was built in the mid‑13th century by the Frankish lord Geoffrey de Bruyère and served as the seat of the barony that bore its name, which comprised a total of twenty‑two fiefs. Its construction was not only an expression of feudal authority but also a strategic choice. Its naturally fortified position made it one of the safest and most important strongholds of western Arcadia, controlling a key passage that linked Arcadia with Messenia and Elia.
During the Greek Revolution, Karytaina assumed a pivotal role. In April 1821, outside the castle—where the Muslim inhabitants of the settlement had taken refuge—the first organized Greek military camp was formed. Commanders from various parts of the Peloponnese gathered there under the leadership of Theodoros Kolokotronis. It was at this site that the first victorious battle of the Revolution in Arcadia was fought. In 1826, faced with the threat posed by Ibrahim’s forces, Kolokotronis repaired the castle, turning it into a refuge for the inhabitants of the wider region. His temporary residence there is associated with what is now known as the “Kolokotronis House,” located on a plateau near the summit of the hill. In addition to the fortifications, the Church of the Panagia of the Castle (13th–14th c.) survives—a small cross‑in‑square church with an exonarthex, attesting to the enduring presence of the Christian community within the settlement. On the right side stands a square tower dating to the Byzantine period, known by the name of the local castellan, Matzouranoyiannis.