Temple of Apollo Palatinus

The Temple of Apollo Palatinus ('Palatine Apollo') was a temple on the Palatine Hill of ancient Rome, which was first dedicated by Augustus to his patron god Apollo. It was only the second temple in Rome dedicated to the god, after the Temple of Apollo Sosianus. It was sited next to the Temple of Cybele. Prior to excavations in 1956, these remains were thought to belong to the Temple of Jupiter Victor.
History.
It was vowed by Octavian in return for the victory over Sextus Pompeius at the Battle of Naulochus in 36 BC and over Mark Antony and Cleopatra at the Battle of Actium 31 BC, and was built on a site where a lightning bolt had struck the interior of Augustus' property on the Palatine. It was dedicated on October 9, 28 BC. The ludi saeculares, reinstituted by Augustus in 17 BC and also largely developed and funded by him, involved the new temple.
Augustus' private house was directly connected to the terrace of the sanctuary via frescoed halls and corridors. This tight connection between the sanctuary and the house of the princeps, both dominating the Circus Maximus, repeated a trope already present in royal palaces of Hellenistic dynasties.
If still in use by the 4th-century, it would have been closed during the persecution of pagans in the late Roman Empire.
Description.
The remains of the building were excavated in the 1960s by Gianfilippo Carettoni, in an area sloping steeply down towards the Circus Maximus. The temple's precinct (the area Apollinis) was an artificial terrace (70 x 30 m), supported on opus quadratum sub-structures. It contained an altar faced with the sculptural group "Myron's Herd", sited together on an elaborate base. In the northern part of this terrace the temple was raised on a high podium, built in blocks of tufa and travertine in the load-bearing parts and elsewhere in cement. The temple itself was in blocks of Carrara marble, with a pronaos as well as a facade of full columns on the front and the same order continued on half columns against the outside walls of the cella.
In the excavations different polychromatic terracotta slabs were recovered with reliefs of mythological subjects (of the "lastre Campana" type).
The adjoining library, the Bibliotheca Apollinis Palatini, according to the Forma Urbis Romae, was constituted from two apsidal halls, with the walls decorated by a row of columns.
Sculptures.
The ancient sources state the temple had ivory doors and held numerous works of sculpture. The pediment included two bas-reliefs of hunting the Galatians, from Delphi, and 6th century BC Chian art, with sculptures of the Niobids by Bupalus and Athenis. The cult group in the cella included a statue of Apollo Citharoedus, possibly by Scopas and perhaps from the sanctuary of Apollo at Rhamnus in Attica; a sculpture of Diana, by Timotheos; and one of Latona, sculpted by Cephisodotus. Into shelves at the basis of the statue of Apollo were placed the Sibylline Books, transferred here from the temple of Jupiter on the Capitol (cf. Suetonius, "Div. Aug." 31.3).
The temple was surrounded by a portico (the portico of the Danaids) with columns in yellow 'giallo antico' marble, and with black marble statues of the fifty Danaids in between the column-shafts, a sculpture of Danaos with his sword unsheathed, and equestrian statues of the sons of Egypt.