The Middle Ages was the time from the fall of the Roman empire until the middle of the 15th century. From 500 to about 800 there was some decline compared with the Roman civilization. European villages were often destroyed and looted by barbarians such as the Vikings. During the High Middle Ages magnificent castles and large churches called cathedrals were built and important works of literature were written. In the later Middle Ages, there was a plague called the Black Death. The Black Death killed one-third to one-half of Europe's population.