Pallene was an ancient deme of Attica, located at the base of Keraies hill, which Euripides called "the sacred hill of Athena Pallenis." Around 440-425 BC, an architect known to scholars only as the Theseum architect - because he also built the Temple of Hephaestus, the Temple of Poseidon at Sounion, and the Temple of Nemesis at Rhamnous - constructed a Doric hexastyle peripteral temple here for Athena, with Apollo worshipped alongside her. The temple was 35 meters by 16. Its alignment pointed precisely toward Delos, Apollo's birthplace. The four nearby demes - Pallene, Acharnae, Gargettus, and Paeania - formed a religious league centered on this sanctuary. Mythology layered on top: Theseus had defeated his cousins the Pallantidae here, on his way to unifying Attica. The cult was important. The location was rural. For four centuries the temple stood quietly on the hill while Athens itself rose, fell, and rose again.

Around 2 BC, during the reign of Augustus, the Athenians made a remarkable decision. They dismantled the temple at Pallene block by block and brought it to the Agora. As they took it apart, masons carved a unique identifier on each block. They cut out the high-relief friezes by chiseling away the feet of the figures, then levering the blocks free with crowbars. They moved the entire structure - 230 fragments of which have been recovered and identified - to a new foundation in central Athens, where they reassembled it on top of recycled foundation stones from the destroyed Hellenistic Arsenal. They aligned the new temple with the Odeon of Agrippa, just built by Augustus' son-in-law. They added new sculptures appropriate to the Augustan moment - Nereids riding dolphins as eastern corner acroteria, possibly a reference to the naval victory at Actium. Most importantly, they rededicated the building. It was no longer Athena's temple. It was now the Temple of Ares.

An inscription on a statue base records that the community of Acharnae dedicated a thank-offering "to Ares and Augustus" when one Apollophanes was priest of Ares. Acharnae had hosted Athens' main cult of Ares since the 4th century BC. A second base in the Agora was inscribed to Gaius Caesar, Augustus' grandson, hailed as "the New Ares." Gaius visited Athens in 1 BC. He died in AD 4. Ares was the Greek equivalent of Mars, and Augustus had dedicated the great Temple of Mars Ultor in Rome in 2 BC. The transferred Athenian temple aligns with that imperial program: a Greek temple to a Greek war god, brought to the heart of Athens, with strong genealogical ties between the imperial family and Mars/Ares. The Athenians appear to have been participating, voluntarily or otherwise, in Augustus' Roman religious renewal. They had a beautiful 4th-century temple sitting in the countryside; the emperor wanted Ares honored in Athens; they moved the temple.

Pausanias visited the temple in the 2nd century AD. He recorded its cult statues. Ares himself was attributed to the sculptor Alcamenes, an Athenian working in the late 5th century BC. The Borghese Ares, a statue now in the Louvre, has been identified since the 19th century as a Roman copy of Alcamenes' work: a beardless young man, naked, weight on his left foot, a shackle ring around his right ankle. The shackle is unusual. Scholars suggest it represented a magical insurance policy: the Athenians chained their war god so that victory would never leave them. A second statue in the temple was the Athena of Locrus of Paros, the original cult image from Pallene, brought along with the building. Two statues of Aphrodite stood with them, possibly reconceived in the Augustan move as references to Venus, ancestor of Augustus' Julian family. The whole interior had been quietly translated into a statement of Roman imperial theology, even as it preserved the older gods who had stood in their proper places at Pallene.

The temple stood in the Agora for nearly three centuries. Around 270-300 AD - probably after the Herulian sack of Athens in 267 - much of the roof was spoliated to build the post-Herulian fortification wall. A statue of Athena from the west pediment was damaged and discarded at this time. By the 5th century, Christians had begun systematically defacing the surviving sculptures, removing the breasts of the female figures with the methodical violence of zealots. Sometime in the 6th century AD, the building was finally demolished. Heads were chopped off. Statues were burned in lime kilns to make plaster - the most common late-ancient fate for marble. The foundations were excavated by the American School of Classical Studies in 1937 and reburied in 1951 to protect them from winter flooding. Today the outline of the temple is marked by stones laid on the surface. The original foundations at Pallene were finally excavated in the 1990s, when the site became a residential suburb. Two empty footprints, one in the city and one in the suburbs, remember the same temple in two places.