The argument is that Canadian and American historians need significant knowledge of European or Asian history if they are really to understand their own special subject—for at least three reasons. Without a significantly different subject to serve for comparison and contrast, the understanding of any given subject is impossible. The vast majority of our citizens/residents or their ancestors contributed a great part of their cultural heritage to our society. And 300 to 500 years is too chronologically shallow for anyone to grasp adequately the historical process. To illustrate the usefulness of such collateral knowledge, the experiences of four distinct European regions—the middle Danube, the Netherlands, the British Isles, and the Delian League of Ancient Greece—are briefly traced, with North American "applications" sometimes stated and sometimes left to be discerned. The concluding arguments stress the uniqueness of history in emphasizing TIME (the chronological environment) and the need to think metaphorically for understanding and communicating one's subject (the metaphors come from significantly different historical experiences, as well as from the arts).