The gospels of Matthew, Mark, and Luke report a disputation between Jesus and some questioners. The latter tried to trap Jesus into taking a stand on whether Jews should or should not pay taxes to the Roman authorities. Jesus demanded that they bring him a coin of the kind they might use to pay those taxes. They brought him a denarius, and he answered, 'render unto Caesar the things that are Caesar's, and unto God the things that are God's.'
This meant: Money you may give to the emperor – it is his domain. God, however, is the master of your life, and as such has a totally different claim to you than just taxes.
We may be almost certain that the coin in question was one like this, a denarius of Emperor Tiberius (14-37 AD). Such coins were mass-produced and circulated in all provinces of the Roman Empire at that time.