Thomas Cahill, in his book How the Irish Saved Civilization, argues that Irish monks played a crucial role in preserving and transmitting classical learning during the early Middle Ages. After the fall of the Western Roman Empire, much of Europe was plunged into chaos and violence. Many libraries were destroyed, and the knowledge contained in them was lost. However, Irish monks established monasteries throughout Europe, where they copied and preserved manuscripts of classical works. They also taught Latin, which became the common language of scholars throughout Europe. As a result, Irish monks played a vital role in preserving and transmitting the classical learning that would eventually form the basis of Western civilization.