When Yaakov and Eisav are born we are told of their eternal battle. Bereishit (25:23):
וַיֹּאמֶר יְהוָה לָהּ, שְׁנֵי גֹיִים בְּבִטְנֵךְ, וּשְׁנֵי לְאֻמִּים, מִמֵּעַיִךְ יִפָּרֵדוּ; וּלְאֹם מִלְאֹם יֶאֱמָץ, וְרַב יַעֲבֹד צָעִיר.
Rashi comments that as one will rise the other will fall i.e. they represent an eternal battle. In VaYishlach, Yaakov returns and encounters Eisav and refers to himself as the 'eved' ('slave'). Chapter 36 is then devoted to Eisav's lineage and kingship. Despite 36:31 saying "וְאֵלֶּה, הַמְּלָכִים, אֲשֶׁר מָלְכוּ, בְּאֶרֶץ אֱדוֹם--לִפְנֵי מְלָךְ-מֶלֶךְ, לִבְנֵי יִשְׂרָאֵל" (i.e. the kings of Eisav), does this mean that when the Israelite Kings rule then "וְרַב יַעֲבֹד צָעִיר" despite the fact that Israelite kingship also ends (albeit at a later date).
Some may suggest that in defeating Amalek is the fulfilment of "וְרַב יַעֲבֹד צָעִיר", but annihilation is not the same as subservience that is suggested by the verse.
Was "וְרַב יַעֲבֹד צָעִיר" a prophecy that was already fulfilled at a certain time - if so when? Is it a general prophecy for the 'end of days'? Is "וְרַב יַעֲבֹד צָעִיר" to be understood more conceptually as the 'schools of thought' of Yaakov and Eisav, etc?