1938 until April 1939. In the mid-1930s, Hitler began pursuing an increasingly aggressive foreign policy; in 1936 he re-militarized the Rhineland, and in 1938 completed the Anschluss of Austria and the annexation of the Sudetenland. He then demanded German control over the city of Danzig, which had become a free city after World War I. World War II Early on 1 September 1939, Germany launched an invasion of Poland. Schleswig-Holstein had been positioned in the port of Danzig, moored close to the Polish ammunition depot at Westerplatte under the guise of a ceremonial visit in August. Around 04:47 on 1 September, Schleswig-Holstein opened fire with her main battery at the Polish positions on the Westerplatte, and in doing so fired the first shots of World War II. These shots were the signal for ground troops to begin their assault on the installation, though the first German ground attack in the Battle of Westerplatte was repelled shortly thereafter. A second assault began later that morning, again supported by Schleswig-Holstein, though it too had failed to break into the installation by around noon. Schleswig-Holstein was joined on 4 September by the torpedo boats T196 and Von der Gröben. A force of German infantry and army engineers went ashore to take the depot, with heavy fire support from Schleswig-Holstein. The Poles managed to hold off the Germans until they were forced to surrender on 7 September at 10:30. Following the Polish surrender, Schleswig-Holstein began shelling Polish positions at Hel and Redłowo; these operations lasted until 13 September. Between 25 and 27 September, the old battleship returned to Hel with her sister Schlesien; both vessels conducted further bombardments of Polish positions there. On 25 September the Schleswig-Holstein was lightly damaged by Polish coastal batteries at Hel. The German military then turned its attention westward, and in April 1940 invaded Denmark. Schleswig-Holstein was assigned to Gruppe 7, a part of the naval component for the German invasion force for Denmark. Along with the torpedo boat Claus von Bevern and several auxiliary ships, her objective was to support the capture of Korsør and Nyborg. During the invasion, the ship was briefly grounded in the Great Belt, west of Agersø. Following the operation, she was transferred back to training duties, as the flagship of the Chief of Training Units. At the end of 1943, the reactivation of Schleswig-Holstein was once again contemplated. In her favor was the