History of Cologne was considered a substitute for the German University of Strasbourg, which became part of France along with the rest of Alsace. Cologne prospered during the Weimar Republic and progress was made especially in governance, city planning and social affairs. Social housing projects were considered exemplary and were copied by other German cities. As Cologne competed to host the Olympics, a modern sports stadium was erected at Müngersdorf. Beginning of the 1920s civil aviation was permitted once more, and Cologne Butzweilerhof Airport soon became a hub for national and international air traffic, second in Germany only to Berlin Tempelhof Airport. At
Cologne School of Painting Cologne School of Painting The term Cologne School of Painting was first applied in the 19th century to describe old German paintings generally. It subsequently came to refer more specifically to painters who had their workshops in medieval Cologne and the lower-Rhine region from about 1300 to 1550 (; ). Initially smaller altarpieces such as the Klaren Altar in the Cologne Cathedral from about 1360–70 were created, based on book paintings from around the year 1300 . The mid-15th century is the high-point of this school, when Stefan Lochner (active 1442–1451) created the "Altar of the City Patrons", which is