If you haven't read the Appendices to the Lord of the Rings, but you've seen the movies, you might be wondering how Aragorn can be the descendant of Elendil and Isildur and yet he's seemingly a random wanderer far from Gondor. Wonder no more, because I'm going to explain the history of the other kingdom of the Dunedain: the northern kingdom of Arnor.
Oh, and that awesome map of Middle Earth? Get it (with 3 others) here: https://www.amazon.com/Maps-Tolkiens-Middle-earth-Brian-Sibley/dp/061839110X/ref=sr_1_2?ie=UTF8&qid=1493809054&sr=8-2&keywords=maps+of+middle+earth