Frankish Greece in the context of "Pietro Cornaro"

William of Villehardouin (French: Guillaume de Villehardouin; Kalamata, c. 1211 – 1 May 1278) 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.

In the early 1250s, William was the most powerful ruler of Frankish Greece. Most neighboring Frankish rulers acknowledged his suzerainty. In 1255, he laid claim to the northern terziere, or third, of the Lordship of Negroponte on the island of Euboea. Although the two other rulers of Negroponte were his vassals, they rejected his claim. They gained the support of Venice, Guy I de la Roche, Lord of Athens, and other Frankish rulers. The conflict developed into a war of succession that caused much destruction in Euboea and mainland Greece. After William's victory in Attica in May 1258, Guy and his allies surrendered. Guy was tried for his disloyalty but was allowed to keep his Achaean fiefs.

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 (the "triarchs") 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.

Othon de la Roche, also Otho de la Roche (died before 1234), 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 Battle of Halmyros, known by earlier scholars as the Battle of the Cephissus or Battle of Orchomenos, was fought on 15 March 1311, between the forces of the Frankish Duchy of Athens and its vassals under Walter of Brienne against the mercenaries of the Catalan Company, resulting in a decisive victory for the mercenaries.

Engaged in conflict with their original employers, the Byzantine Empire, the Catalan Company had traversed the southern Balkans and arrived in southern Greece in 1309. The new Duke of Athens, Walter of Brienne, hired them to attack the Greek ruler of neighbouring Thessaly. Although the Catalans conquered much of the region for him, Walter refused to pay them and prepared to forcibly expel them from their gains. The two armies met at Halmyros in southern Thessaly (or at the Boeotic Cephissus, near Orchomenos, according to an earlier interpretation). On the Athenian side, many of the most important lords of Frankish Greece were present. The Catalans were considerably outnumbered and weakened by the reluctance of their Turkish auxiliaries to fight. They did have the advantage of selecting the battleground, positioning themselves behind marshy terrain, which they further inundated. Walter, a prideful man and confident in the prowess of his heavy cavalry, charged headlong against the Catalan line. The marsh impeded the Frankish attack and the Catalan infantry stood firm. The Turks re-joined the Company and the Frankish army was routed, with Walter and almost the entire knighthood of his realm falling in the field. Subsequently the Catalans took over the leaderless Duchy of Athens, ruling that part of Greece until the 1380s.

Walter VI of Brienne (c. 1304 – 19 September 1356) was a French nobleman and crusader. He was the count of Brienne in France, the count of Conversano and Lecce in southern Italy and claimant to the Duchy of Athens in Frankish Greece.

Maria of Enghien, also known as Marie of Enghien or d'Enghien (after 1363–1392/1393), was the Lady of Argos and Nauplia in Frankish Greece from 1376 or 1377 to 1388. She inherited the estate from her father, Guy of Enghien, when she was a minor. Her paternal uncle, Louis of Enghien, served as her regent. Louis gave Maria in marriage to a Venetian patrician, Pietro Cornaro, in 1377. Maria moved to Venice, but she was involved in the administration of her lordship. After her husband died, she sold the lordship to the Republic of Venice for a regular income in 1388.

Nerio I Acciaioli or Acciajuoli (full name Rainerio; died 25 September 1394) served as the de facto Duke of Athens from 1385 to 1388 and ruled uncontested until his death in 1394. Born into a family of Florentine bankers, he became the principal agent of his influential kinsman Niccolò Acciaioli in Frankish Greece in 1360. He acquired extensive estates in the Principality of Achaea, which he administered independently of the absent princes. In 1374 or 1375, he hired mercenaries and captured Megara, a strategically significant fortress within the Catalan-ruled Duchy of Athens. His forces invaded the duchy again in 1385, driving back the Catalans to the Acropolis, which they were ultimately compelled to surrender in 1388.

Nerio and his son-in-law, Theodore I Palaiologos, Despot of the Morea, invaded the Lordship of Argos and Nauplia in the Peloponnese. Nerio seized Nauplia, but the Venetians soon expelled his troops from the town. In 1389, he was captured by the Navarrese mercenary commander Pedro de San Superano, and released only after pledging to support the Venetian effort to take Argos from Theodore. As security for this promise, he ceded parts of his domains to Venice, though he failed to persuade his son-in-law to surrender Argos. In 1390, Nerio's forces captured the Duchy of Neopatras from the Catalans, but the Ottoman sultan Bayezid I conquered the territory in 1393, after which Nerio paid him an annual tribute for Athens. On 11 January 1394, King Ladislaus of Naples, who claimed suzerainty over Frankish Greece, invested Nerio with the Duchy of Athens. In his last will, Nerio divided his possessions among his younger daughter, Francesca, his illegitimate son, Antonio, and the Church of Saint Mary (the Parthenon) of Athens.