When that the Romans begin worshiping the son god
When that the Romans start worshiping the sun
The Romans worshiped Sol throughout Rome’s history. Sol Indiges was the first solar deity in Rome’s history. However, Sol Indiges was not very popular and it was not until the introduction of Sol Invictus in which there was an official state recognized worship of Sol. Sol Invictus, which means the unconquered sun, was the official sun god of the late Roman Empire created by the emperor Aurelian in 274 AD. There are no earlier references to the cult before this time.