So as title really.
Typically I've seen many people argue that a Roman Empire that recovers Egypt (and later Africa) wouldn't have an interest, or would be too late to the game to take advantage of the New World when found (possibly by someone 100 years before).
However, assuming that the Roman Empire fights for it, and has some success, I'm curious as to the importance of holding (and the later effects of that) on Spain? Lets assume that this is a Better First Crusade scenario where the Romans have the Levant restored and later conquer Egypt (so weird Latin issues in the Levant, peripheral to focus).
What are the impacts of Spain being both the gateway between the Old and New Empires? Would the capital move from Constantinople? Or at least where the Emperor rules (minor difference I know).
---- CLARIFICATION ----
1) First Crusade is a good and long-lasting change for the Roman Empire.
2) This eventually leads to the reconquest of Egypt and Africa. (Italy optional).
3) The New World is found.
4) The Romans express an interest in the new world, and are triumphant (i.e. they have a significant hand in the New World).
5) Assume that Spain succeeded at its reconquista.
What does this do to Spain?