The Battle of Saint George took place on 9
September 1320 between the Latin Principality of Achaea and the forces of the Byzantine
governor of Mystras, at the fortress of Saint George in Skorta in Arcadia. As a result of the battle,
Arcadia, the heartland of the Morea, came firmly under Byzantine control. From c. 1315 on, the Latin Principality of Achaea, which controlled most of
the Morea (Peloponnese) peninsula in southern Greece, entered a period of instability, as the princely title was disputed
by multiple claimants. A Catalan invasion in 1315 in support of the claims of Isabella of Sabran was defeated at the Battle
of Manolada in 1316, but Prince Louis of Burgundy died soon after, leaving his title contested between his wife, Matilda of
Hainaut, the Angevins of Naples, who as the Principality's liege lords forced her to marry the Angevin John of Gravina, and
Louis' brother Odo IV, Duke of Burgundy. An Angevin baillie, Frederick
Trogisio, was sent to govern the Principality in 1318, but it was not until 1322 that the matter was settled, with
Odo's claims bought by the Angevins and Matilda effectively confined in Naples. In contrast to the turmoils of the Principality
of Achaea, the Byzantine province of Mystras, encompassing the southeastern Morea, during
the same period (1316–c. 1323) came under
the steady and effective governance of Andronikos Asen, a nephew of the Byzantine emperor
Andronikos II Palaiologos. A capable leader, Asen pursued the perennial war against the Latins of Achaea with considerable
vigour.
According to the French and Aragonese versions of the Chronicle
of the Morea, in 1320 Asen launched a campaign into Arcadia, the central region of the Morea, and laid siege to the castle
of Saint George in Skorta. The castle had been built by the Latins in the early 1290s, and was
part of a chain of fortresses guarding the passes of the mountains of Skorta. It had already been lost to the Byzantines by
treachery in c. 1294, and recovered by the Latins
at some unknown date after. In response, the baillie Trogisio assembled an army to relieve the castle,
calling on the vassals of the principality for assistance: among them were the Bishop of Olena,
James of Cyprus, the Grand Constable Bartholomew II Ghisi, and the commanders of the Knights of St. John and of the Teutonic Knights in Achaea.
Learning of the Latins' approach, Asen intensified the siege, and on 9 September, its Greek castellan, Nicoloucho of
Patras, surrendered. Taking possession, Asen left the banners of Achaea flying, so as to mislead the relief force. The ruse
succeeded, and as the Achaean army approached the castle in the belief that it was still held by their allies and that the
Byzantines had abandoned the siege, Asen sprang his trap. The Byzantines were victorious in the battle, and killed many of
the Latins, including the commander of the Teutonic Knights. Many others were taken prisoner, including Bartholomew Ghisi
and the Bishop of Olena. The latter was immediately set free, while Ghisi and the rest were taken to Constantinople. In
the same campaign — the Aragonese and French versions disagree on whether this happened before or after the siege of
Saint George — the Byzantines went on to secure, by bribing their commandants, the castles of Karytaina, Akova, and
Polyphengos.
Aftermath
Asen's 1320 campaign secured the Arcadian plateau for the Byzantines, and reduced
the Principality of Achaea to the western and northern coasts of the Morea, encompassing the modern prefectures of Messenia,
Elis, Achaea, Corinthia, and Argolis. The fortresses that for fifty years had formed a defensive bulwark against the Byzantine
endeavours to expand their province were now lost. At this time, many of the Latin settlers in Arcadia, many of whom may have
had Greek mothers, abandoned the Catholic Church and went over to Greek Orthodoxy. The
Byzantine successes, and the manifest inability of their Angevin suzerains to protect them, led the leading barons of the
principality to send the Franciscan prior Peter Gradenigo to the Doge of Venice in June
1321, offering the principality, as well as the suzerainty over the Lordship of Negroponte,
to the Republic of Venice. Nothing came of these proposals, but a new Angevin baillie, Ligorio Guindazzo, arrived
some time in 1321. His tenure was brief—about a year—and unremarkable. During the same time, John of Gravina
began preparing an expedition to the Morea, but it was not until January 1325 that the Prince of Achaea left Italy for his
principality, with 25 galleys, 400 cavalry, and 1,000 infantry. He occupied Cephalonia and restored Angevin control over
Achaea, as the barons and vassal lords of Latin Greece came to pay him homage, but his attempt to recapture Karytaina failed
due to the energetic resistance of its garrison, the raids launched by the Byzantine governor into Latin territories, and
the approach of winter. In spring 1326, John of Gravina again departed the Morea, leaving its governance once again to short-lived
baillies. The Duke of Naxos, Nicholas I Sanudo, whom John of Gravina left in charge
of military operations, managed to defeat a larger Byzantine army raiding the principality in a hard-fought battle soon
thereafter, but this was not enough to check Byzantine power in the Morea in the long term.