Taking over land, goods and people is a very human thing to do, not localized to europe. There were nations (tribes, kingdoms, whatever) trying to occupy europe too, both from the south and east... and let's not forget the many many internal european wars and conquests.

Looking globally, europeans were really that much more advanced (in science, warfare, medicine, logistics,...) than the areas they managed to occupy... how else would a few people on a few boats occupy whole continents? Did those people do a lot of very very bad things (from slavery to genocide) ... sure. Was there some luck involved? Sure... the romans were more advanced than the occupying tribes and they still lost. But generally, the more advanced groups were the winners.