The Early Middle Ages in Western Europe (450-900 CE) was a difficult time of invasion and weakness. Literacy was low, confined mainly to monasteries. The Feudal system and Manorialism developed, with serfs living under difficult conditions on manors. However, starting around 900 CE, agricultural innovations increased food production and population growth. Towns and trade expanded, and a recovery was underway in Western Europe. Universities also began developing. By the High Middle Ages, Western civilization reached new heights in the 1100-1200s CE.