History of the Agora
The excavations of the Athenian Agora have uncovered about thirty acres on the sloping ground northwest of the Acropolis (Fig. 3). Material of all periods from the Late Neolithic to modern times has been excavated, shedding light on 5,000 years of Athenian history. The area was occupied long before it became the civic center of Athens. During the Late Bronze Age it was used as a cemetery, and some 50 graves have been found, dating from 1600 to 1100 B.C. These are mostly chamber tombs, with multiple burials. It continued in use as a cemetery throughout the Iron Age (1100–700 B.C.) and over 80 graves, both burials and cremations, have been found. Several dozen wells reflect the position of houses and indicate that the area was given over to habitation as well.
[King Cyrus speaks]: "'I have never feared men who have a place set apart in the middle of their city where they lie and deceive each other. If I keep my health, the Hellenes will have their own sufferings to worry about, not those of the Ionians.' This threat he uttered against all Hellenes because they have agoras and buy and sell there; for the Persians themselves do not use agoras, nor do they have any." (Herodotos 1.153)
A gradual change from private to public land seems to have occurred during the middle of the 6th century, and the first certain public buildings or monuments (Southeast Fountain House , Altar of the Twelve Gods ) were erected in the 520s, during the tyranny of the Peisistratids. The creation of the new democracy in 508/7 B.C. led to the construction of the Old Bouleuterion on the site of the later Metroon , the setting of boundary stones , and, perhaps, the construction of the Royal Stoa .
The Persian destruction of 480/79 left the city a shambles, but the buildings in the Agora were repaired and many more were added in the 5th and 4th centuries to accommodate the Athenian democracy at its height. The Stoa Poikile , Tholos , New Bouleuterion , Stoa of Zeus Eleutherios , South Stoa I , Mint , and Lawcourts  were all added to the periphery of the great square, as were fountain houses, temples, and shops.
The rise of Alexander of Macedon eclipsed Athens politically and the 3rd century B.C. saw Athens dominated by his successors. Recovery in the 2nd century was fueled by Athens’ reputation as the cultural and educational center of the Mediterranean, and the philosophical schools founded by Plato, Aristotle, Zeno, and Epicurus flourished. Three large stoas were built in the Agora in the 2nd century (Middle Stoa , South Stoa II , and Stoa of Attalos ) and the archive building (Metroon ) was rebuilt with a colonnaded facade.
The influence of Rome becomes clear in Athens in 86 B.C., when Sulla besieged the city after it sided with Mithradates of Pontus. Despite this poor choice, the city flourished, thanks again to her reputation for education and culture. Temples were built in the Agora to accommodate worship of the imperial family , and a great Odeion  or concert hall was set down in the middle of the square late in the 1st century B.C. Athens prospered through the 2nd century under the emperor Hadrian (A.D. 117–138) and is described in detail by the traveler Pausanias in the years around A.D. 150.
Hard times began in the 3rd century, when the city was destroyed by northern invaders, the Herulians, in A.D. 267. When the city was rebuilt, the old Agora was not even within the new fortified circuit . The area was given over to a variety of large villas in the 4th and 5th centuries A.D. The buildings show the effects of further barbarian incursions: Visigoths under Alaric in A.D. 395, the Vandals in the 470s, and the Slavs in 582/3. The area was abandoned in the 7th century and only recovered with the growth of the city in the 10th century A.D.