Synodality. Autocephaly can only be granted by common consent of the whole Church.
Autocephaly. The Church of Georgia was an Autocephalous Church when Moscow annexed it.
Canon VIII of the Third Ecumenical Synod
"...The same rule shall hold good also with regard to other Diocese and Churches everywhere, so that none of the Bishops Most-Beloved by God shall take hold of any other province that was not formerly and from the beginning in his Jurisdiction, or was not, that is to say, held by his predecessors. But if anyone has taken possession of any and has forcibly subjected it to his authority, he shall re-give it back to its rightful possessors, in order that the Canons of the Fathers be not transgressed, nor the secular fastus be introduced, under the pretext of Divine Services”