Monte Cassino Monastery, founded by St. Benedict on the hills of Monte Cassino near Rome, Italy, in the Middle Ages, pioneered the formation of European culture and civilization and the development of Western medicine with its rich library and hospices where monks were educated and also served the patients. However, it was an important center of science and culture, offering a retreat to the leading scientists of its time (they were translating the works of Eastern scientists into Latin). Benedict's rule had three basic principles: peace, reading, and manual labor. The monastery established close relations with political and religious authorities, as it enjoyed the support of the nobility and also recruited the children of the aristocracy into its ranks. Later, with many monasteries and a chain of monasteries established in line with the teachings of St. Benedict, he contributed to the formation of the cultural and political map of Europe. He had indirect influences on the events of his time through his close relations with the leading religious and political actors of his age (papacy and royalty, nobility). During the reform movement, it was one of the leading figures of its time. And also supported the reforms of Pope Gregory VII. During the abbacy of Desiderius II. the monastery had good relations with the East Roman Empire, and as due result Byzantine art was imported to the West. In addition, it played an active role in the First Crusade by hosting the Crusaders on their way and with the loans it gave. The Abbey of Monte Cassino significantly influenced the scientific, cultural, and political life of Europe. This study aims to explore the impact of Benedictine Monte Cassino Monastery on Western Europe’s scientific, cultural, and political arena.