In ancient times, the city was known as Kyparissieis and is mentioned in the Homeric epics as part of Nestor’s kingdom, which participated in the Trojan War. An important harbour and commercial centre during the Hellenistic and Roman eras, the ancient city occupied the lowland and coastal areas of the modern one. During the Early Byzantine period, likely between the 6th and 8th centuries, it was renamed Arkadia and developed in the area of the castle and the present-day Upper Town. According to one interpretation, the name change reflects the resettlement of Arcadian inhabitants following the incursion of Slavic tribes into the Peloponnesian hinterland.

After the fall of Constantinople during the Fourth Crusade (1204), Arkadia Castle was one of the few places in the Peloponnese that mounted strong resistance to the Frankish knights. Following a prolonged siege in 1205/6, it became the seat of the barony of the same name, a fief under William of Champlitte, the ruler of the Principality of Achaia. In 1208, it passed as a hereditary fief to his successor, Geoffrey I of Villehardouin. In 1262, the barony passed to Vilain d’Aulnay, while in the middle of the 14th century, it passed to the Le Maure family, which had other fiefdoms in Messenia, and then, in the late 14th century, to Centurione Zaccaria, prince of Achaia.

After 1430, Arkadia, along with the remaining territories of the Principality of Achaia, was granted as a dowry to Thomas Palaiologos, the son-in-law of Centurione Zaccaria, and became part of the Despotate of the Morea until 1460, when the Ottomans abolished it. Under Ottoman rule, Arkadia continued to flourish and was the seat of a kaza (administrative district).

In 1686, the castle was besieged and captured by the Venetians. Before abandoning it, the Ottomans set fire to and blew up its towers. During the brief period of Venetian rule that followed, the castle declined in importance, as its location was now considered vulnerable. Nevertheless, it remained the seat of an administrative district (territorio) and maintained a Venetian garrison. In 1715, along with the rest of the Peloponnese, it was recaptured by the Ottomans, who, in the 18th century, conducted limited repairs to the walls and towers.

In 1770, during the Orlov Revolt, the castle suffered extensive damage. On 27 March 1821, the Ottomans surrendered Arkadia to the Greeks, but in 1825, both the castle and city were destroyed by Ibrahim Pasha’s forces. In 1833, Arkadia was renamed Kyparissia, and its castle permanently lost its military function. A powerful earthquake in 1886 caused significant damage to both the castle and the city.