Will and Ariel Durant's "The Story of Civilization" is a good survey resource.

http://en.wikipedia.org/wiki/The_Story_of_Civilization

Volume IV covers the Middle Ages quite well. I really enjoyed reading the whole thing when I was 10-12 years old. They are very fair to all civilizations.

The key event of the Middle Ages in Europe was the seizure of the Templar estates in 1307-1309 and the resulting economic contraction that followed that set the stage for the Great Famine of 1315-1325 where half the population died. Europe very nearly collapsed. Many parts of Europe have never recovered.