Severinus of Cologne was a Christian bishop and missionary who lived during the 4th century. He is best known for his efforts to spread Christianity in the region of Cologne, which is located in present-day Germany. His work contributed to the establishment of the Christian faith in this area, and he is often remembered for his dedication to his mission. Severinus is also recognized as a saint in the Catholic Church and is celebrated for his piety and leadership. His feast day is observed on October 23, honoring his contributions to the early Christian community and his role in the development of the church in Germany.