"Viribus Unitis" and "Tegetthoff" were commissioned into the fleet in December 1912 and July 1913, respectively. "Prinz Eugen" followed in July 1914. The smaller shipyards in Fiume resulted in a slower construction which was further delayed by the outbreak of the war, with "Szent István" commissioned into the fleet in December 1915. This was too late for her to take part in the Bombardment of Ancona in which the remaining ships in the class saw action immediately following Italy's declaration of war on Austria-Hungary in May 1915.