The Kingdom of God: Past, Present or Future?

Our working definition for The Kingdom of God is: the rule of God. On the basis of that definition, when did the Kingdom begin?

We all agree that some NT passages refer to a future (coming) realization of the Kingdom. Nevertheless, God's reign was recognized since OT times:

"...the LORD Almighty, who is enthroned between the cherubim." (1Sa 4.4)
"The LORD reigns!" (1Ch 16.31)
"The One enthroned in heaven laughs..." (Ps 2.4)
"The LORD reigns forever, he has established his throne for judgment." (Ps 97)
"The Lord reigns, he is robed in majesty." (Ps 93.1)
"Say among the nations, 'The LORD reigns.'" (Ps 96.10)
"The LORD reigns, let the earth be glad." (Ps 97.1)
"The LORD reigns forever..." (Ps 146.10)
"O LORD Almighty, God of Israel, enthroned between the cherubim, you alone are God over all the kingdoms of the earth." (Isa 37.16)
"You, O Lord, reign forever, your throne endures from generation to generation." (Lam 5.19)

On the basis of such passages, we recognize that the Kingdom of God has, at least in some sense, existed since the beginning. I welcome your comments!