Old Pylos castle is a 13th-century fortress near Pylos, Greece. It is one of two castles guarding the strategic bay on which it sits; the other is New Pylos castle. It is also known by its historical Italian and Turkish names, respectively Old Navarino and Anavarin-i atik. Locally, it is simply Palaiokastro (Greek: Παλαιόκαστρο, "old castle"). The castle sits atop an imposing 200-m rock formation on the northern edge of the bay, flanked by sheer cliffs; the naturally defensible site has probably been occupied since classical times.
The castle was built in the late 13th century by Nicholas II of Saint Omer, the lord of Thebes in the Principality of Achaea, one of the Latin states ruling Greece following the Fourth Crusade. By the mid-14th century it belonged to the Genoese, who used it as a base in their conflicts with Venice, raiding Venetian colonies in Messenia. In the 1360s, the castle was occupied by Marie de Bourbon during her attempt to claim the Principality following the death of her husband, Robert of Taranto. By 1381, the castle is found in the hands of the Navarrese Company.
The Venetians attempted to purchase the castle several times, worried about the threat it posed to their trading interests; they occupied it in 1417 to prevent the Genoese from doing so, and finally secured its sale from the Prince of Achaea, Centurione II Zaccaria, in 1423. Venetian control survived the First Ottoman–Venetian War of the late 15th century, but not the Second War at the turn of the 16th. Following the Venetian defeat in the Battle of Modon (1500), the Pylos garrison simply surrendered when the forces of Bayezid II arrived from Modon, despite significant strength and ample provisions.
Upon gaining control of the region, the Ottomans constructed New Pylos castle (Anavarin-i cedid) on the southern end of the bay, and the old castle lost importance. The new castle better covered the main practical entrance to the bay towards the south, especially as the narrower northern entrance was blocked in 1571 by ships scuttled during the Battle of Lepanto; the new site also had a more secure water supply. By the late 16th century, the old castle had only a token garrison, and it became increasingly dilapidated and partly ruined through the 17th century. During the Morean War, the Ottomans concentrated their defenses at the new castle, and the old castle's 100-man garrison surrendered to the Venetians without a battle on June 2, 1686.
The Venetians considered either improving or demolishing the fortress, but ended up making few modifications before it was retaken by the Ottomans in 1715, during the Seventh Ottoman–Venetian War. Neither were any major repairs or improvements made by the Ottomans, though it was garrisoned with a token force. When the Ottomans retreated in 1828 during the Greek War of Independence, the French Morea expedition found the castle essentially a ruin.
