Urban II (Pope 1088 - 1099) is given the credit for getting the events started which were to change the Middle Ages. Earliest writers seemed to call it a pilgrimage, but it was the special privilege to carry weapons that change this into what has become called "The Crusades". [ ca. 1095 - ca. 1291] The following are readings that give several views into this period of our history. I call them, a picture book, a story book, and a study book.
A picture book:
For those who like lots of pictures (like me) this book is for you.
A story book:
A study book: