When the Greek ruler of
Thessaly,
John II Doukas, died in 1318 without an heir, his domains fell into chaos. The
Almogavars of the
Catalan Company, who had
recently conquered most of the
Duchy of Athens to the south of Thessaly, took advantage of the situation to push north. Led by
Alfonso Fadrique, the Catalans took
Neopatras in 1319, and by 1325 had also conquered
Zetounion,
Loidoriki,
Siderokastron and
Vitrinitsa, as well as—apparently briefly—
Domokos,
Gardiki and
Pharsalus. The central and northern part of Thessaly remained in Greek hands under a series of local magnates, some of whom recognized
Byzantine suzerainty, like
Stephen Gabrielopoulos of
Trikala; others, however, like the Maliasenos family around
Volos, turned to the Catalans for support. The Greek rulers of Thessaly had long, but erroneously, been known as "Dukes of Neopatras" by Western European contemporaries from their capital, modern
Ypati; this was a result of confusion from the family name of
Doukas, which Western Europeans mistook as the title of "duke". As a result, the territory conquered by the Catalans in Thessaly was organized as the "Duchy of Neopatras" and was divided into five
captaincies. The Catalans selected the infant
Manfred, son of King
Frederick III of Sicily, as their duke, but actual power was wielded by the Duke's local representative, the
vicar-general, as well as by the marshal () as the elected head of the Company members. Most of the Duchy's possessions in Thessaly were lost when the region was conquered by the
Serbs of
Stefan Dushan in 1348, but Neopatras and the region around it remained in Catalan hands. In 1377, the title of Duke of Athens and Neopatras was assumed by
Peter IV of Aragon. It was preserved among the subsidiary titles of his successors, and was regularly included in the
full title of the
Spanish monarchs at least until the
takeover of the Spanish crown by the
House of Bourbon. In 1378–79, the Aragonese lost most of their possessions in
Boeotia to the
Navarrese Company, while from the south the ambitious Florentine adventurer
Nerio Acciaioli, lord of
Corinth, took over
Megara in 1374 and began applying pressure on Athens. By 1380, the Catalans were left only with the two capitals of Athens and Neopatras, as well as the
County of Salona. Athens fell to Acciaioli in 1388, and in 1390 he captured Neopatras as well. Acciaioli could boast in the title "Lord of Corinth and of the Duchy of Athens and Neopatras", but his triumph was short-lived: in 1393/4 the
Ottoman Turks conquered Neopatras and the entire
Spercheios River valley. Ecclesiastically, Neopatras largely corresponded to the
Latin Archbishopric of Neopatras (), which had one suffragan: Zetounion (Lamia). Among the Catalan archbishops was
Ferrer d'Abella, who tried to have himself transferred to a west European
see. == Dukes of Neopatras ==