Temple of Apollo Sosianus

The Temple of Apollo Sosianus (previously known as the Apollinar and the temple of Apollo Medicus) is a Roman temple dedicated to Apollo in the Campus Martius, next to the Theatre of Marcellus and the Porticus Octaviae, in Rome, Italy. Its present name derives from that of its final rebuilder, Gaius Sosius.

The Apollinar and its successors can closely be linked to the site next to the theatre due to Ascanius's reference to it being "outside the porta Carmentalis between the Forum Holitorium and the Circus Flaminius", Livy's placing it in the prata Flaminia (Flaminian meadows, as this area was then called) and other references placing it near to the forum, the Capitol and the theatre of Marcellus respectively. All these indicate the presently-accepted site for this temple, just north of the theatre and east of the porticus Octaviae, on the street leading through the porta Carmentalis to the campus Martius, a little south of the present Piazza Campitelli.

The three columns of the temple which survive to full-height today belong to the Augustan rebuild, but the cult of Apollo had existed in this area since at least to the mid-5th century BC when an Apollinar (a sacred grove or altar) was recorded on this site. Since Apollo was a foreign cult, it thus legally had to be placed outside the pomerium, making it a regular spot for extra-pomerial senate meetings (This was also Apollo's only temple in Rome until Augustus dedicated another on the Palatine Hill.)

The first temple building dates to 431 BC, when the consul Gnaeus Iulius Mento inaugurated one dedicated to Apollo Medicus (the doctor), in fulfilment of a vow to him during a plague of 433 BC. This building was restored in 353 BC, and perhaps in 179 BC, when the censor Marcus Aemilius Lepidus and his colleague let the contract for building a porticus from the temple to the Tiber, behind the temple of Spes The censor's projects also included a nearby theatre. The shedding of tears for three days by a cult-statue of Apollo, cited among the prodigies at the death of the Younger Scipio, can only have occurred at this temple, there being no others to Apollo.

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