After serving its initial purpose as a religious temple, the interior of the Erechtheion was repeatedly converted to adapt to the cultural heritage of the conquerors. The building underwent numerous changes into the 6th century Byzantium period which refashioned the temple into a basilica church. The simple forms of the Erechtheion provided an adequate layout for the complex designs associated with Christian churches, the large open spaces being utilised as ‘baptisteries’ and ‘sacristies’ for the most important clergymen. With the 13th century invasion of the Franks, the Acropolis once again transitioned into a grandiose residence dedicated to the Catholic bishop. After the Frankish stronghold was undermined
by the Ottomans in 1458, the building served as a housing unit for the army commanders. During the Venetian attacks of 1687, the Erechtheion fell into a state of disrepair no longer fit for housing. Thereafter, the North Porch functioned as a gunpowder storage while the rest of the structure slowly decayed into an unusable ruin, the last remnants destroyed after the War of Independence from 1821 to 1833. After the 19th century, the Erechtheion provided precedent for Neoclassical buildings in Europe and in contemporary times, serves as an impressive reminder of the Ancients.
Thus the Erechtheion is not only unique for its unprecedented asymmetric design but also for its ability to endure and transition through the ages. The dedication to the religious idols of Athens provided a strong hold during times of political and economic instability. The building then continued to function throughout the invasion of different ruling empires and into the contemporary times as an ancient historical ruin.