Quoting the Bible:

"Is it lawful to give tribute to Caesar, or not? Shall we give, or shall we not give? But He, knowing their hypocrisy, said unto them, Why temp ye me? Bring me a penny, that I may see it. And they brought it. And He saith unto them, Whose is this image and superscription? And they said unto Him, Caesar's. And Jesus, answering, said unto them, Render to Caesar the things that are Caesar's and to God the things that are God's (Mark 12:14-17)"

Who the Caesars Were

Julius Caesar, the famous military commander and dictator of Rome was the originator of the name Caesar that the Roman emperors adopted. Augustus being an adopted heir of Julius Caesar, also took on his name. This was an important political tactic giving him the power of Julius Caesar as an adopted son. An adopted son would therefore carry the popularity that Caesar had. Augustus was Roman emperor from 27 B.C. - 14 A.D., officially. Upon his death, the next emperor was Tiberius. He, too, as later emperors assumed the title of Caesar in his name, especially written on coins. So therefore, Caesar was a name that many emperors assumed and put on their coins.

Types of Silver Coins bearing the name "Caesar" in Circulation during the Life of Jesus Christ

When the 1611 edition of the King James Bible was written, the term for Roman denarius whose Greek equivalent was the drachm was translated to the Anglo-Saxon penny as known to the British, which was their standard silver coin denomination at the time.

So we know three rulers who would have had a denarius silver coin with the name "Caesar" written on them. And they would be.

• Julius Caesar, died March 15th, 44 B.C.
• Augustus, Roman emperor who ruled 27 B.C. - 14 A.D.
• Tiberius, Roman emperor who ruled 14 A.D. - 37 A.D.

Most Likely Candidates for the Coin Described in the Bible

Quoting the section from Mark, "Whose is this image and superscription?". We must come to the conclusion that the coin must, have a portrait of a ruler and also have a "superscription" or in other words the word Caesar in the title and be a coin of the denarius (or possibly drachm) denomination. Although the coins of Julius Caesar did exist in denarius form with his portrait, they are quite rare, and would not have been minted since 44 B.C., so likely would not be a common type of coin in circulation at the time, although certainly a candidate.

Then there are the coins of Augustus, who feature the word "Caesar" whom also had the denarius coin with his portrait and who issued a lot of them in his reign from before Jesus' birth to his young adulthood from 27 B.C. - 14 A.D. So this would be a more likely candidate for the coin that was brought before Jesus Christ.

And lastly, the most traditionally attributed coin as being the Tribute Penny is the silver denarius coin of emperor Tiberius, whom reigned 14-37 A.D. and also feature the title of Caesar on them. These would have been the most recently-minted coins in the context of the time period  described and therefore the most widely-accepted form of the Tribute Penny.

Conclusion

In conclusion, the coin that was talked about in the bible would have to have four characteristics.

1. Would have to have been minted during the lifetime or before the birth of Jesus Christ.
2. Would be silver and of the Roman denarius denomination.
3. Would have the portrait of the Roman ruler on it.
4. Would have the word "Caesar" in the inscription on them

So therefore they would be portrait Julius Caesar silver denarius coins, Augustus silver denarius coins, or Tiberius silver denarius coins with the inscription of "Caesar" on them.