The Scandinavian expansion included Danish and Norwegian as well as Swedish elements, all under the leadership of Rollo. By the end of the reign of Richard I of Normandy in 996 (aka Richard the Fearless / Richard sans Peur), all descendants of Vikings became, according to Cambridge Medieval History (Volume 5, Chapter XV), 'not only Christians but in all essentials Frenchmen'. During the Middle Ages, the Normans created one of the most powerful feudal states of Western Europe. The Normans conquered England and southern Italy in 11th century, and played a key role in the Crusades.