The temples built in the Forum Romanum during the Imperial era (27 B.C. – A.D. 476) were largely built to commemorate mortal men who had been deified after death. These were usually Emperors of Rome who had been particularly influential and popular.
Temple of Caesar – Built in honor of Julius Caesar by Augustus in 29 B.C., this temple stood at the eastern boundary of the Forum Romanum. The temple's location is significant: it is the spot where the murdered dictator of Rome had been cremated. As Emperor, Augustus began a tradition of deifying (making the mortal man into a god) leaders post mortem, the first being Caesar. Thus the Temple of Caesar is in fact a temple to a god, and not merely a mortal man.
Temple of Vespasian and Titus – Begun in A.D. 79 by Titus to commemorate his father, the deified Emperor Vespasian, this temple was completed by Domitian about ten years later. It was rededicated to both Vespasian and Titus at that time. Restorations were completed later by Septimius Severus and Caracalla.
Temple of Venus and Rome – this was the largest temple in the Forum Romanum as well as the city itself, and was dedicated to Venus, the Roman goddess of love, in the form of Venus Felix (Venus of good fortune) and Roma Aeterna (Eternal rome). The temple was quite resplendent, because of its grand importance to the people of Rome. It was designed and built by Emperor Hadrian, during his impressive building campaign throughout the city, and completed in A.D. 135. It featured a unique design that incorporated two cellas, one housing a statue of Venus Felix that faced the Forum, and one housing a statue of Roma Aeterna facing the Colosseum. It was built on an enormous platform, and featured ten columns across the front. The temple required restoration in A.D. 307 due to fire, and was rebuilt by Maxentius.
Temple of Antoninus and Faustina – Built by Antoninus Pius in A.D. 141, this temple honored the Emperor's wife, Faustina, who had just died. It was rededicated when he died and was deified in A.D. 161. It stands today in seemingly excellent condition, but this is due in part to the fact that it was converted to the Church of San Lorenzo in Miranda in the 7th century A.D. The remains of the original Roman temple were incorporated, and the church was built on its site.
Temple of Romulus – Dedicated to Romulus, son of Maxentius, and not the mythical founder of Rome, this circular temple was built in A.D. 307. When Romulus died, his father commissioned the temple, as well as had him deified. The temple was rededicated by Constantine after the Battle at the Mulvian Bridge in A.D. 312 (constantine had rededicated all of Maxentius' monuments after this victory). Today, a portion of the site of this temple lies within the basilica of Santi Cosma e Damiano, and has since the 6th century A.D.