Solar deities are a dime a dozen in the ancient world. Ra, Surya, Tonatiuh, Malakbel, Amun/Aten, Albina, Helios, Arinna, Ah Kin, Koyash, Nahundi and dozens of other have all had their day in the sun. All of them basically boiled down to the same sun. I’m partial to the late sun gods and their imagery.
Helios was the main solar deity for the Greeks. He drove a chariot pulled by solar steeds across the sky. Apollo was also closely related to the sun. Apollo was an Olympian and Helios a Titan. Homer considered them to be independent, but Pseudo-Eratosthenes clearly equated them.
The Romans called Helios Sol Invictus, a popular figure on sarcophagi (above right) and the walls of Pompeii (left). They saw Apollo as a separate deity, but, confusingly, their Apollo often appears in the guise of Sol. They also managed to weave Mithras, who was very popular in Rome around the third century, into the sun picture as well. Unlike the static depictions of gods by the Greeks, Roman religious imagery, including that of the early Christians, was full of action and expression.
Sol appears occasionally on 1st and 2nd century coinage, and very often through the 3rd and 4th centuries. Although Sol worship was sufficiently popular in the 5th century for Augustine to rail about it, the last known appearance of a Roman Sol inscription is from around 390 AD. Romans then started preferring Jesus to Sol Invictus and lively Christian imagery replaced good ol’ Sol. More on that to follow.