Over the centuries – even in the present – how have the people living in Europe developed a separate “European” identity by contrasting themselves with an external (and/or internal) “other”, defined religiously, culturally, racially, or any other way?

Over the centuries – even in the present – how have the people living in Europe developed a separate “European” identity by contrasting themselves with an external (and/or internal) “other”, defined religiously, culturally, racially, or any other way?