It is really quite simple:
Rev 12:1 BBE And a great sign [G4592, semeion] was seen in heaven: a woman clothed with the sun, and with the moon under her feet, and on her head a crown of twelve stars.
Rev 12:2-5 BBE 2 And she was with child; and she gave a cry, in the pains of childbirth. 3 And there was seen another sign in heaven; a great red dragon, having seven heads and ten horns, and on his heads seven crowns. 4 And his tail was pulling a third part of the stars of heaven down to the earth, and the dragon took his place before the woman who was about to give birth, so that when the birth had taken place he might put an end to her child. 5 And she gave birth to a son, a male child, who was to have rule over all the nations with a rod of iron: and her child was taken up to God and to his high seat.
Most people miss this because the KJV says wonder, instead of sign.
Mat 24:30 KJV And then shall appear the sign [G4592, semeion] of the Son of man in heaven: and then shall all the tribes of the earth mourn, and they shall see the Son of man coming in the clouds of heaven with power and great glory.
It is the time when Jesus will leave the Father's side, placing all enemies under his feet. When he returns with the saints, at the parousia, he will be given the kingdom, to rule with a rod of iron over all the nations. The sign is actually the new Jerusalem surrounded by the 12 angels of Rev 21:12.
Dan 7:14 KJV And there was given him dominion, and glory, and a kingdom, that all people, nations, and languages, should serve him: his dominion
is an everlasting dominion, which shall not pass away, and his kingdom
that which shall not be destroyed.
Rev 11:15 KJV And the seventh angel sounded; and there were great voices in heaven, saying, The kingdoms of this world are become
the kingdoms of our Lord, and of his Christ; and he shall reign for ever and ever.
Psa 110:1-5 KJV 1 A Psalm of David. The LORD said unto my Lord, Sit thou at my right hand, until I make thine enemies thy footstool. 2 The LORD shall send the rod of thy strength out of Zion: rule thou in the midst of thine enemies. 3 Thy people
shall be willing in the day of thy power, in the beauties of holiness from the womb of the morning: thou hast the dew of thy youth. 4 The LORD hath sworn, and will not repent, Thou
art a priest for ever after the order of Melchizedek. 5 The Lord at thy right hand shall strike through kings in the day of his wrath.
Heb 1:13 KJV But to which of the angels said he [GOD] at any time, Sit on my right hand, until I make thine enemies thy footstool?
Blessings