The answer is Diocletian. We explain this in the chapter called the Deity of Christ, part 1 in our book: D. James Kennedy, Ph.D., and Jerry Newcombe, D.Min., The Real Messiah: Prophecies Fulfilled (www.coralridge.org). The paragraph explaining Diocletian is set off by ***

        The Deity of Jesus Christ was foretold in the Old Testament as well as many other aspects of His life. Because the subject is so important, we have devoted three chapters to it, beginning with this one.

THE CORONATION OF CHRIST
        At first glance, Psalm 2:7 seems to be referring to Christ’s birth. Yet, when we read Paul’s explanation of these verses in the New Testament, he applies them to the Resurrection. How can this be? Where did Paul get the idea of a resurrection from a passage that speaks of a Son being "begotten?"
        The key to understanding Paul’s interpretation of this verse is found when we recognize that it is cradled in a passage which appears to have been used in the coronation ceremonies of the Davidic kings. During these ceremonies, God symbolically called the new king a "Son." The reason he received this title from God was that the king represented God’s covenant faithfulness, and the Almighty’s rule over Israel. In that light, Paul’s use of this verse indicates that it was at the Resurrection that Jesus was crowned as God’s Messianic King. This happened after His ascension when He came home in triumph and was seated at the right hand of the Father.
        Like much of prophetic literature, the second Psalm blends a historical prediction and Messianic promise. This Psalm is based on God’s promise to King David that he would have a Son who would be given a great kingdom by God. Historically, this prophecy was first fulfilled in the rule of King Solomon. Yet, the complete realization occurred when Jesus was awarded the Messianic throne.
        Here is the second Psalm in its entirety:

Why do the nations rage
   and the peoples plot in vain?
The kings of the earth set themselves,
   and the rulers take counsel together,
   against the LORD and against his anointed, saying,
"Let us burst their bonds apart
   and cast away their cords from us."
He who sits in the heavens laughs;
   the Lord holds them in derision.
Then he will speak to them in his wrath,
   and terrify them in his fury, saying,
"As for me, I have set my King
   on Zion, my holy hill."
I will tell of the decree:
The LORD said to me, "You are my Son;
   today I have begotten you.
Ask of me, and I will make the nations your heritage,
   and the ends of the earth your possession.
You shall break them with a rod of iron
   and dash them in pieces like a potter's vessel."
Now therefore, O kings, be wise;
   be warned, O rulers of the earth.
Serve the LORD with fear,
   and rejoice with trembling.
Kiss the Son,
   lest he be angry, and you perish in the way,
   for his wrath is quickly kindled.
Blessed are all who take refuge in him (ESV).
        This is, undoubtedly, one of the clearest Old Testament passages describing the work and ministry of the Messiah. In it, we are forewarned that the kings of the earth will take counsel together to disrupt the plans of God’s "anointed." This prophecy was fulfilled by the actions of Herod, Pontius Pilate and the Jewish leaders, leading to the crucifixion of Jesus. All nations, both Jewish and Gentile, conspired to put an end to the Messianic claims of Jesus Christ (Acts 4:26).
        In another sense, one could argue that this sort of anti-Christian bigotry and persecution goes on in our own day. In our context, we see a war against anything Christian in the public arena; but in some countries, Christians are killed for their faith. Yet all of these anti-Christian rulers are warned to "kiss the Son," i.e., to pay Him homage. None of their attempts to stop the kingdom of heaven will succeed.
        ***A classic example of this took place about three hundred years after Christ. A Roman emperor, Diocletian, was a terrible persecutor of the faith. He was one of the worst of the emperors to try and stop the Christian movement. He not only had Christian Scriptures gathered up and burned, but he had Christians killed because they were Christians. It was as if Diocletian was saying, You can worship Jesus Christ—over my dead body. After his reign, Constantine became the emperor and declared Christianity legal. Meanwhile, Diocletian’s grave became the cornerstone of a church. For centuries now, Christians have worshiped in that building—if you will—over Diocletian’s dead body. No human can stop the Kingdom of God.***
        Psalm 2 also points out God’s attitude toward such intrigues. God is pictured as laughing with scorn at these vain attempts to frustrate His eternal and unchangeable plan of redemption. The rulers of the earth desired to be free of God’s rule; yet, God in His power and sovereignty used their rebellion to fulfill His purpose of salvation and establish His Kingdom (Acts 4:28).
Though men killed Jesus in an attempt to escape the rule of the Almighty, God raised Him from the dead and set Him upon David’s throne as the chosen and eternal Son. Jesus, as the Divine Prince, was inaugurated, crowned, and given the Kingdom by His Father on ascension day.

Click here for more information on The Real Messiah: Prophecies Fulfilled.

Click here to try a previous quiz.