Koroni occupies a promontory commanding the southwestern Peloponnese and sea routes around Cape Akritas. Ancient and Byzantine settlement preceded the medieval fortress, and the site changed hands as powers competed for ports after the Fourth Crusade. Venice secured Koroni in the early thirteenth century and developed it with Methoni as one of the republic's two principal stations in the region. Their harbors sheltered ships traveling between the Adriatic and the eastern Mediterranean, while fortifications protected merchants, officials, soldiers, residents, and supplies.

Under Venetian rule Koroni became a fortified colonial town rather than a castle occupied only by troops. Walls enclosed houses, churches, storehouses, and administrative buildings. The port handled agricultural products and served pilgrims, diplomats, and fleets on long voyages. Together Koroni and Methoni were called the “eyes” of Venice because they watched the routes toward Crete and the Levant. Repeated repairs responded to artillery and to the vulnerability of an overseas possession surrounded by territories ruled by other powers.

Ottoman forces captured Koroni in 1500 during a wider war with Venice. The population and religious landscape changed under Ottoman administration, although earlier structures continued to be reused. In 1532 Andrea Doria seized the fortress for the Habsburg emperor during campaigning against the Ottomans, attracting Christian refugees and hopes of a lasting reversal. Ottoman forces recovered Koroni in 1534, and many residents departed with the withdrawing fleet. The brief occupation demonstrated how Mediterranean strategy could transform local communities as abruptly as it changed garrisons.

Venice regained Koroni in 1685 during the Morean War and held it until the Ottoman reconquest of 1715. The fortress remained Ottoman until the Greek struggle for independence. In 1828 French troops of the Morea Expedition took control as Ottoman-Egyptian forces withdrew, helping transfer the region to the developing Greek state. By then the enclosure contained buildings from many periods, and settlement extended beyond its walls. Military technology and new political borders reduced the need for a heavily fortified port.

Koroni remained inhabited and religious communities continued to use parts of the enclosure, distinguishing it from a wholly abandoned ruin. Conservation must therefore address archaeological remains, standing fortifications, churches, vegetation, homes, and active community life together. Earthquakes, coastal weather, and repairs have altered the walls, but the broad circuit still shows the scale of Venetian and Ottoman investment. Koroni Castle records how a harbor could connect a small Peloponnesian town to commerce, pilgrimage, imperial rivalry, population movement, and the creation of modern Greece across more than six centuries.