How/when did the concept of Europe and Europeans emerge?

by bananaramentor

I came across a reference from a letter from general von Gneisenau to his wife during the Napoleonic Wars stating "this battle will decide the fate of Europe " . Which begs the question; when and how did the concept of Europe and Europeans come to be? Also what decided if one was European?

qed1

I've dealt with at least the first part of this question, when did the concept of Europe emerge, before here.