Explanation: The Roman Emperor Elagabalus (sharing their name with the sun god they were the high priest of) attempted to change the Roman pantheon, rather radically, in appointing the Syrian sun god Elagabalus over Jupiter as the chief god of the Roman pantheon. This, uh, was not a popular move, and did not outlast Elagabalus's reign.
Funny enough, later Emperors would have more success in implementing sun worship of Sol Invictus, the Unconquerable Sun, though there is significant scholarly debate over whether Sol Invictus owed more to eastern sun worship traditions, or had roots in traditional Roman worship of Sol Indiges.