The rock was first fortified during the Archaic period (7th-6th centuries BC). The walls of Acrocorinth were tied into the enclosure that protected the lower city, so creating a powerful defensive system; Later on, the Long Walls were added to protect communication with the port of Lechaio. The fortifications of Acrocorinth were repaired in the 4th century BC or in the first half of 3rd, but suffered extensive damage during the levelling of Corinth by the Roman general Lucius Mommius in 146 BC. A possible refortification of parts was made in the 5th or 6th centuries AD, at which time the walls of the hill were independent from the contemporary Byzantine fortifications of the city of Corinth.
During the transitional period (7th century AD-843), Acrocorinth played an active role in the city of Corinth, which was then the capital of the theme of Greece (687-694) and later of the Peloponnese (786-788). However, the castle gained greater importance in the following centuries, at a time when the city became a major commercial and administrative centre. Indeed, in Middle Byzantine sources the city of Corinth is referred to as trading-post or town, to distinguish it from the city that had developed on the Acrocorinth, the so-called castle.
A critical period began for the city of Corinth with its capture by the lord of Nafplio, Leon Sgouros, in 1204 and the stiff resistance put up against the crusader army of Geoffrey Villehardouin, who took it in 1210. After its incorporation into the Principality of Achaia, Corinth became an important economic and strategic centre and the seat of the Latin bishop. The castle was intensively inhabited at that time, as is indicated by fragments of imported pottery and coins from the West of the 13th and 14th centuries. Gradually, from its 14th century heyday, the city began to decline, mainly due to the instability caused by the conflicts between the Mystra Byzantines and the Franks, by the raids of the Catalans and Turks, but also because of natural disasters such as the earthquake of 1320 and the plague epidemic in 1348. In 1358, the city came to the Florentine merchant dynasty of the Acciaioli, in 1395 to the despot of Mistra Theodore Palaiologos, then to the Knights of St John in the period between 1400 to 1404, at which point it returned to Theodore Palaiologos again, until its capture by the Turks in 1458.
Acrocorinth continued to be of strategic importance for the new conquerors, and extensively inhabited. The space between the second and third lines of circuit walls was intended for the Christian population to live in, whilst that within the inner enclosure was reserved for the Ottomans. The castle remained active in its defensive role during the first period of Turkish rule (1458-1687) and the second (1715-1827), as well as during the intermediate Venetian rule (1687-1715): repairs were carried out and new elements included because of the use of firearms.
Χρονολόγηση: Early Byzantine period (4th -7th centuries), transitional period (7th - 9th centuries), Middle Byzantine period (9th - early 13th centuries), Frankish/Late Byzantine periods (13th - 15th centuries), Ottoman/Venetian periods (15th - 19th centuries)