her sisters Hannover and Schlesien and several of the Braunschweig-class battleships. Schleswig-Holstein was recommissioned as the new fleet flagship on 31 January 1926 following an extensive refit, with new fire controls and an enlarged aft superstructure for the admiral's staff. The secondary 17 cm guns were replaced with pieces and four 50 cm torpedo tubes were fitted in main deck casemates fore and aft, replacing the submerged tubes. Schleswig-Holstein and her sister Hannover went on a training cruise into the Atlantic that lasted from 14 May to 17 June 1926; while on the cruise, she visited Palma de Mallorca in the Mediterranean from 22 to 30 May. She stopped in Barcelona with from 1 to 7 June, and then proceeded to Vigo from 12 to 14 June, where she joined Hessen, Elsass, and Hannover. There, the chief of the fleet, Vice Admiral Konrad Mommsen, met with King Alfonso XIII. Schleswig-Holstein went on another training cruise between 30 March and 14 June 1927 into the Atlantic. She visited a series of Iberian ports, including Lisbon, Portugal, where Mommsen was greeted by Óscar Carmona, the president of Portugal. In December 1927 Schleswig-Holstein went back into dock, re-emerging in January 1928 with her forefunnel trunked back into the second and both remaining funnels heightened, as had previously been done with her sister Schlesien. With the delivery of the new Panzerschiffe (armored ships) beginning in 1933, the older battleships were gradually withdrawn from front-line service. In May 1935, the Reichsmarine was reorganized as the Kriegsmarine by the reforms instituted by Adolf Hitler that created the Wehrmacht. Schleswig-Holstein ceased to be fleet flagship on 22 September 1935, and was refitted as a cadet training ship during January–March and May–July 1936. The changes included removing her remaining upper deck 15 cm guns and her torpedo tubes, and her two aft boiler rooms were converted to oil-firing models, although the forward boilers remained coal-fired. The ship's standard complement was also reduced from 35 officers and 708 enlisted men to 31 officers and 565 sailors. The crew was supplemented by 175 cadets, who were taken on long cruises in Schlesien and Schleswig-Holstein, the latter sailing in October 1936 on a six-month voyage to South America and the Caribbean. The following year, her cruise took her around Africa, and the 1938–1939 cruise went back to South American and Caribbean waters. Gustav Kieseritzky served as the ship's commander from June