in order to protect the battleships against a possible shell landing on the turrets and the imminent explosion resulting from such a hit. The conning tower of the ships had of armor plating, while the bulkheads inside the battleship that separated different compartments were thick. Construction The Erzherzog Karl class, like the Habsburg class before them and the Radetzky class after them were named after archdukes of the Austro-Hungarian Royal Family, specifically Archduke Charles, Duke of Teschen, Maximilian I of Mexico and Archduke Friedrich, Duke of Teschen. The ships were all laid down at the Stabilimento Tecnico Triestino in Trieste. The first ship of the class, was laid down on 24 July 1902. Following 15 months of construction she was launched on 4 October 1903 and finally commissioned into the Austro-Hungarian Navy on 17 June 1906. The next ship of the class was . She was laid down on 4 October 1902 and launched on 30 April 1904. Erzherzog Friedrich was finally commissioned into the Austro-Hungarian Navy on 31 January 1907. The third and final ship of the Erzherzog Karl class was . She was laid down on 9 March 1904 and later launched on 21 May 1905. She was commissioned into the navy on 21 December 1907. Ships Service history At the outbreak of World War I the three ships formed the III division of the Austrian-Hungarian battle-fleet and spent most of the war based at Pola. The members of the Erzherzog Karl class were mobilized on the eve of the war to support the flight of and . The two German ships were attempting to break out of Messina, being chased by the French Navy and the Royal Navy, and make their way to Turkey. The breakout succeeded. When the flotilla had advanced as far south as Brindisi in south eastern Italy, the Austro-Hungarian ships were recalled. In company with other units of the Austro Hungarian Navy the class took part in the bombardment of Ancona on May 24, 1915. There they expended 24 rounds of 240 mm armor-piercing shells at signal and semaphore stations as well as 74 rounds of 190 mm shells aimed at Italian gun-batteries and other port installations. A major mutiny among crews of the armored cruisers stationed in Cattaro, including and , began on 1 February 1918. Two days later, the three Erzherzog Karl-class ships arrived in the port and assisted with the