The Principality of Achaea or Principality of Morea was one of the vassal states of the Latin Empire, which replaced the Byzantine Empire after the capture of Constantinople during the Fourth Crusade. It became a vassal of the Kingdom of Thessalonica, along with the Duchy of Athens, until Thessalonica was captured by Epirus in 1224. After this, Achaea became the dominant power in Greece, lasting continuously for 227 years and cumulatively for 229.
The Battle of Pelagonia or Battle of Kastoria took place in early summer or autumn 1259, between the Empire of Nicaea and an anti-Nicaean alliance comprising Despotate of Epirus, Kingdom of Sicily and the Principality of Achaea. It was a decisive event in the history of the Eastern Mediterranean, ensuring the eventual reconquest of Constantinople and the end of the Latin Empire in 1261.
William of Villehardouin was the fourth prince of Achaea in Frankish Greece, from 1246 to 1278. The younger son of Prince Geoffrey I, he held the Barony of Kalamata in fief during the reign of his elder brother Geoffrey II. William ruled Achaea as regent for his brother during Geoffrey's military campaigns against the Greeks of Nicaea, who were the principal enemies of his overlord, the Latin Emperor of Constantinople Baldwin II. William succeeded his childless brother in the summer of 1246. Conflicts between Nicaea and Epirus enabled him to complete the conquest of the Morea in about three years. He captured Monemvasia and built three new fortresses, forcing two previously autonomous tribes, the Tzakones and Melingoi, into submission. He participated in the unsuccessful Egyptian crusade of Louis IX of France, who rewarded him with the right to issue currency in the style of French royal coins.
The Prince of Achaea was the ruler of the Principality of Achaea, one of the crusader states founded in Greece in the aftermath of the Fourth Crusade (1202–1204). The principality witnessed various overlords during its more than two centuries of existence, initially, Achaea was a vassal state of the Kingdom of Thessalonica under Boniface I of house Montferrat, then of the Latin Empire of Constantinople under the houses of Flanders-Courtenay, which had supplanted the Byzantine Empire, and later of the Angevin Kingdom of Naples. During the Angevin period, the princes were often absent, represented in the Principality by their baillis, who governed in their name. After 1404 the principality became sovereign as the Genoese Centurione II Zaccaria bought from the Neapolitan crown the princely rights.
The Battle of the Olive Grove of Kountouras took place in the summer of 1205, in Messenia in the Morea peninsula, between the Frankish Crusaders and the local Byzantine Greeks, resulting in a victory of the Franks and the collapse of the local resistance.
William I of Champlitte (1160s-1209) was a French knight who joined the Fourth Crusade and became the first prince of Achaea (1205–1209).
The Villehardouin family was a noble dynasty that originated in Villehardouin, a former commune of the Aube department, now part of Val-d'Auzon, France. It is most notable as the ruling house of the Principality of Achaea, a Frankish crusader state in the Peloponnese peninsula of Greece, between 1209 and 1278, when possession passed to the Angevin Kings of Naples.
Geoffrey I of Villehardouin was a French knight from the County of Champagne who joined the Fourth Crusade. He participated in the conquest of the Peloponnese and became the second prince of Achaea.
Othon de la Roche, also Otho de la Roche, was a Burgundian nobleman of the De la Roche family from La Roche-sur-l'Ognon. He joined the Fourth Crusade and became the first Frankish Lord of Athens in 1204. In addition to Athens, he acquired Thebes by around 1211.
The War of the Euboeote Succession was fought in 1256–1258 between the Prince of Achaea, William of Villehardouin, and a broad coalition of other rulers from throughout Frankish Greece who felt threatened by William's aspirations. The war was sparked by Villehardouin's intervention in a succession dispute over the northern third of the island of Euboea, which was resisted by the local Lombard barons with the aid of the Republic of Venice. The Lord of Athens and Thebes, Guy I de la Roche, also entered the war against William, along with other barons of Central Greece. Their defeat at the Battle of Karydi in May/June 1258 effectively brought the war to an end in an Achaean victory, although a definite peace treaty was not concluded until 1262.
Glarentza, also known as or Clarenia, Clarence, or Chiarenza, was a medieval town located near the site of modern Kyllini in Elis, at the westernmost point of the Peloponnese peninsula in southern Greece. Founded in the mid-13th century by William II of Villehardouin, the town served as the main port and mint of the Frankish Principality of Achaea, being located next to the Principality's capital, Andravida. Commerce with Italy brought great prosperity, but the town began to decline in the early 15th century as the Principality itself declined. In 1428, Glarentza was ceded to the Byzantine Despotate of the Morea, and served as its co-capital, being the residence of one of the Palaiologos despots, until the Ottoman conquest in 1460. Under Ottoman rule, Glarentza declined rapidly as the commercial links with Italy were broken, and by the 16th century was abandoned and falling into ruin. Little remains of the town today: traces of the city wall, of a church and a few other buildings, as well as the silted-up harbour.
The Battle of Makryplagi or Makry Plagi was fought between the forces of the Byzantine Empire, and the Latin Principality of Achaea. The Byzantines had been weakened and demoralized by the defection of their numerous Turkish mercenaries to the Achaeans. At Makryplagi, the Byzantines suffered a heavy defeat, which together with their defeat at the Battle of Prinitza the previous year ended their attempted reconquest of the Morea.
The Barony of Karytaina or of Skorta was a medieval Frankish fiefdom of the Principality of Achaea, located in the Peloponnese peninsula in Greece, centred on the town of Karytaina in the mountainous region known as Skorta.
The Barony of Arcadia was a medieval Frankish fiefdom of the Principality of Achaea, located on the western coast of the Peloponnese peninsula in Greece, and centred on the town of Arcadia, ancient and modern Kyparissia.
Vilain of Aulnay was a French knight from Aulnay-l'Aître in the Champagne who became marshal of the Latin Empire of Constantinople and first Baron of Arcadia in the Principality of Achaea. In the Greek version of the Chronicle of the Morea, he is attested as Βηλὲς ντὲ Ἀνόε, a form which passed to the other versions of the Chronicle as Anoé, Annoée or Anoée.
Geoffrey of Briel, in older literature Geoffrey of Bruyères, was a French knight and the third lord of the Barony of Karytaina in the Principality of Achaea, in Frankish Greece. He led a colourful and turbulent life, narrated in detail in the Chronicle of the Morea. Accounted the finest knight in the Principality, he fought in the wars against the Byzantine Greeks, was captured in the Battle of Pelagonia in 1259, and was sent back to Achaea bearing the Byzantine terms in 1261. Geoffrey was twice deprived of his barony, once for rebelling against his uncle, the Prince of Achaea William II of Villehardouin, and then for abandoning the Principality without leave in order to spend time with a mistress, the wife of one of his feudatories, in Italy. He was pardoned both times, but henceforth held his title as a gift of the Prince. He died childless in 1275, and the Barony of Karytaina was split up.
The Treaty of Sapienza was concluded in June 1209 between the Republic of Venice and the newly established Principality of Achaea, under Prince Geoffrey I of Villehardouin, concerning the partition of the Peloponnese (Morea) peninsula, conquered following the Fourth Crusade. By its terms, Venice, which had been accorded most of the Peloponnese in the Partitio Romaniae, recognized Villehardouin in possession of the entire peninsula except for the two forts of Modon and Coron, which came under Venetian control, and secured commercial and tax privileges in the Principality. The text of the treaty is also a valuable primary source for the early history of the Principality of Achaea.
The First Parliament of Ravennika was convened in May 1209 by Latin Emperor Henry of Flanders in the town of Ravennika in Central Greece in an attempt to resolve the rebellion of the Lombard barons of the Kingdom of Thessalonica.
The Second Parliament of Ravennika was convened in May 1210 by Latin Emperor Henry of Flanders in the town of Ravennika in Central Greece in order to resolve the differences between the princes of Frankish Greece and the Roman Catholic clergy of their domains.
The bailli, bailie, or bailiff was the administrative representative of the Princes of Achaea, ruling the Principality of Achaea in the Prince's absence. The early princes, who belonged to the founding Villehardouin dynasty, resided in the principality, and governed it directly. In 1278, Achaea passed to Charles of Anjou, the King of Naples. Charles, and many of his successors, ruled the principality through their baillis, and never visited it in person. Originally, the baillis were Angevin officials, but the post was often given to powerful feudatories from Achaea and the rest of Frankish Greece.
