Religion in Ancient Rome

Roman religion was originally rather vague, with sacred spirits called numina instead of personified figures like those of Greek Mythology. Romans believed that every person, place, or thing had its own genius, or divine soul. As the Roman Republic declined and the Roman Empire came into power, the new emperors were held as gods. This was the beginning of an imperial cult which, as contact with the Greeks increased, became increasingly related to Greek Mythology. The Greek gods influenced the developing Roman religion to the point that, names aside, the characters and stories were completely adopted.
http://en.wikipedia.org/wiki/Ancient_Rome

Temple of Caesar

After the death of Julius Caesar, the senate deified him and elevated him to the status of a god. His adoptive son Augustus Caesar then built a temple in his honor. Caesar was the first of the Romans ever to have a temple built in his honor, but he was certainly not the last. This temple began the transition from private worship to public worship.
http://en.wikipedia.org/wiki/Temple_of_Caesar