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
History of the Jews in Cologne archbishop vacant, but Charles IV was not near enough to take action. On 23–24 August the relative security of Jews in Cologne came to an end. The Jews, who had already faced slaughter in the surrounding territories, were now also killed in Cologne itself. The actual outcome of the pogrom is not well known. In the course of St. Bartholomew's Night in 1349 the Jewish quarter near the town-hall ("Rathaus") was attacked, after which killing, plundering of Jewish properties, and arson followed. Fugitives were pursued and struck down. Though partly contradictory of each other, many sources testify to the calamity.