"And from Jesus Christ, who is...the Prince of the kings of the earth” (Rev. 1:5).

        "Let us look at the kingdom of God as it is described and emphasized in the New Testament.  It should be natural, first of all, for us to take a look at the King of this kingdom!  Unfortunately, the average church member does not think of Jesus as being a King  on this earth.  They see Him in heaven as a Saviour, a great High Priest, a Healer, Blesser, Baptizer, and then — the “soon coming” King!  In thinking so loosely, we rob Jesus of one of the main phases of His ministry, that of being King on this earth — the King of the kingdom of God!  Mind you, He is not GOING to be King; He is King now, for He has already ascended the throne of the majesty on high and been given ALL POWER AND ALL AUTHORITY IN HEAVEN AND IN EARTH.  This is why He can say to all His younger brothers, “To him that overcometh will I grant to sit with me in my throne, even as I also overcame, and am set down with my Father in His throne” (Rev. 3:21)."

Much more in the link:

https://www.kingdombiblestudies.org/Revelation/rev11.htm