c. 1300, reverten, "to come to oneself again, regain consciousness, recover from illness" (senses now obsolete), from Anglo-French reverter, Old French revertir "return, change back," from Vulgar Latin *revertire, variant of Latin revertere "turn back, turn about; come back, return," from re- "back" (see re-) + vertere "to turn" (from PIE root *wer- (2) "to turn, bend").
Meaning "return to a former state or position" is from mid-15c. Of property, "revert to a grantor or his successor," from mid-15c.; in reference to a return to a former habit, practice, custom, etc., from 1610s. In biology, "go back to an earlier, primitive, or ancestral type," 1859. Related: Reverted; reverting.