Most of the buildings that stood to be admired in subsequent eons were built during the Classical era. While a democratic government quickly replaced the Tyranny imposed by the Spartans, construction at the Acropolis never reached high levels again. While Athens rebounded and remained an important intellectual and economic center, Alexander the Great of Macedonia made certain that his conquest eclipsed all previous Greek achievements. In the process, Hellenic culture expanded and flourished away from the traditional center of Athens and the other city-states of the Classical era.
The Pedestal of Agrippas was commissioned by Eumenes II, the King of Pergamon in Hellenistic times to support a composition of four bronze sculptures. A few minor buildings were added, and some modifications of existing structure also occurred during this time.
During the Roman period Augustus built a small circular temple a little to the East of the Parthenon, and Claudius commissioned a grand staircase that led to the Propylaia, while Hadrian ordered major repairs for the damaged by fire Parthenon.
In 267 CE an invasion by the Herouloi (a band of Germanic tribes) had catastrophic results for Athens as the Teutonic hordes razed the entire city which did not recover until 400 years later when in the 4th century CE Teodosius II and his wife Eudoxia the Athenian commissioned a series of important buildings around Athens. The city thrived as it became the intellectual playground for Christians and Pagans alike this time around. The Neo Platonic academy was founded South of the Acropolis to accommodate an expanding influx of students.
Under Justinian however, Christianity was imposed on the city in 529 CE and all Pagan remnants, including all the philosophy schools, were closed forcing Athens to become a provincial town with little culture or influence. The Parthenon was converted to a Christian church dedicated to the Agia Sophia (Devine Wisdom). The Erechtheion also became a Christian church. Devastating raids by Slavs and Saracens shortly after completed the demise of Athens that lasted for almost half a millennia until in 1000 CE when it became a thriving metropolis once again.
In 1205 CE the Francs occupied Athens and they turned the Acropolis into a fortress and ruled the city from the Propylaia, which they converted into a palace. At the same time they converted the Parthenon into a Catholic cathedral, the Notre Dame d’ Athenes.