Principality of Achaea in the context of "Principality of Piedmont"

Pylos (UK: /ˈpaɪlɒs/, US: /-loʊs/; Greek: Πύλος), historically also known as Navarino, is a town and a former municipality in Messenia, Peloponnese, Greece. Since the 2011 local government reform, it has been part of the municipality Pylos-Nestoras, of which it is the seat and a municipal unit. It was the capital of the former Pylia Province. It is the main harbour on the Bay of Navarino. Nearby villages include Gialova, Pyla, Elaiofyto, Schinolakka, and Palaionero. The town of Pylos has 2,568 inhabitants, the municipal unit of Pylos 4,559 (2021). The municipal unit has an area of 143.911 km.

Pylos has been inhabited since Neolithic times. It was a significant kingdom in Mycenaean Greece, with the remains of the so-called "Palace of Nestor" excavated nearby, named after Nestor, the king of Pylos in Homer's Iliad. In Classical times, the site was uninhabited, but became the site of the Battle of Pylos in 425 BC, during the Peloponnesian War. After that, Pylos is scarcely mentioned until the 13th century, when it became part of the Frankish Principality of Achaea. Increasingly known by its French name of Port-de-Jonc or its Italian name Navarino, in the 1280s the Franks built the Old Navarino castle on the site. Pylos came under the control of the Republic of Venice from 1417 until 1500, when it was conquered by the Ottoman Empire. The Ottomans used Pylos and its bay as a naval base, and built the New Navarino fortress there. The area remained under Ottoman control, with the exception of a brief period of renewed Venetian rule from 1685–1715 and a Russian occupation from 1770–71, until the outbreak of the Greek War of Independence in 1821. Ibrahim Pasha of Egypt recovered it for the Ottomans in 1825, but the defeat of the Turco-Egyptian fleet in the 1827 Battle of Navarino and the French military intervention of the 1828 Morea expedition forced Ibrahim to withdraw from the Peloponnese and confirmed Greek independence. The current city was built outside the fortress walls by the military engineers of the Morea expedition from 1829 and the name Pylos was revived by royal decree in 1833.

Morea (Greek: Μορέας or Μωριάς) was the name of the Peloponnese peninsula in southern Greece during the Middle Ages and the early modern period. The name was used by the Principality of Achaea, the Byzantine province known as the Despotate of the Morea, by the Ottoman Empire for the Morea Eyalet, and later by the Republic of Venice for the short-lived Kingdom of the Morea.

The Capetian House of Anjou, or House of Anjou-Sicily was a royal house and cadet branch of the Capetian dynasty. It is one of three separate royal houses referred to as Angevin, meaning "from Anjou" in France. Founded by Charles I of Anjou, the youngest son of Louis VIII of France, the Capetian king first ruled the Kingdom of Sicily during the 13th century. The War of the Sicilian Vespers later forced him out of the island of Sicily, leaving him with the southern half of the Italian Peninsula, known as the Kingdom of Naples. The house and its various branches would go on to influence much of the history of Southern and Central Europe during the Middle Ages until it became extinct in 1435.

Historically, the house ruled the Counties of Anjou, Maine, Touraine, Provence and Forcalquier; the Principalities of Achaea and Taranto; and the Kingdoms of Sicily, Naples, Hungary, Croatia, Albania and Poland.

The fortress of New Navarino (Greek: Νέο Ναυαρίνο; Ottoman Turkish: Anavarin-i cedid) is an Ottoman fortification near Pylos, Greece. It is one of two castles guarding the strategic Bay of Pylos, on which it sits; New Navarino is located in the southern entrance of the bay, while the northern entrance is guarded by the 13th-century Old Navarino castle, built by the Crusaders of the Principality of Achaea. In juxtaposition with the latter, New Navarino is often known simply as Neokastro or Niokastro (Greek: Νεόκαστρο or Νιόκαστρο, "new castle").

Joanna I, also known as Johanna I (Italian: Giovanna I; December 1325 – 27 July 1382), was Queen of Naples, and Countess of Provence and Forcalquier from 1343 to 1381; she was also Princess of Achaea from 1373 to 1381.

Joanna was the eldest daughter of Charles, Duke of Calabria and Marie of Valois to survive infancy. Her father was the son of Robert the Wise, King of Naples, but he died before his father in 1328. Three years later, King Robert appointed Joanna as his heir and ordered his vassals to swear fealty to her. To strengthen Joanna's position, he concluded an agreement with his nephew, King Charles I of Hungary, about the marriage of Charles's younger son, Andrew, and Joanna. Charles I also wanted to secure his uncle's inheritance to Andrew, but King Robert named Joanna as his sole heir on his deathbed in 1343. He also appointed a regency council to govern his realms until Joanna's 21st birthday, but the regents could not actually take control of state administration after the King's death.

Charles III of Naples, also called Charles the Small or Charles of Durazzo (1345 – 24 February 1386), was King of Naples and the titular King of Jerusalem from 1382 to 1386 as Charles III, and also King of Hungary from 1385 to 1386 as Charles II. In 1381, Charles created the chivalric Order of the Ship. In 1383, he succeeded to the Principality of Achaea on the death of James of Baux.

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 principality was one of the longest-lasting of the Latin states in Greece, outliving the Latin Empire itself by 171 years. It did not come to an end until 1432, when the Byzantine prince Thomas Palaiologos inherited the last remnants of the Principality through marriage to the daughter of the last prince, Centurione Zaccaria. With the Principality gone, the title of Prince of Achaea became vacant. However, in 1453 during the great Morean revolt of 1453-1454, John Asen Zaccaria, son of Centurione revived the Principality. He was confirmed as Prince by the Kingdom of Naples, the historical overlords of the Principality since 1267 and by Venice, though in 1455 John was forced to exile.