Well, by definition empires are imperialist. You wouldn't call anything an empire unless it had imperialist aspirations. Empires of course have been there for a long time, from what we read in history books: the Persian Empire, Chinese, Mongolian, Ottoman,. No, the West has not invented that, but what it has invented is mercantilist colonialism, i.e. based on commerce and monopoly, on control of commerce and trade and manufacturing.