Fair enough; but the opening up of The Americas is what allowed Europe to go on and dominate the world. The modern world was that which came under European hegemony due to 1) the rich resources which powered expansion 2) the techno advances in part spurred by selfsame resources 3) the social changes/adaptations needed to exploit the techno changes fully.

Spain may have "already been an empire", but after 1492 it became an incredibly rich and gGobal Empire. I would argue that this is therfore an acceptable dating for what might better be known, perhaps, as the conception rather than the birth.

Whatever. I won't have any objections to the final descision with regard to this.