The SS Ancona was an Italian passenger steamer, built in 1908 by Workman, Clark & Co., Ltd., Belfast, and operated by the Society di Navigazione a Vaporetti Italia, of Genoa. She was torpedoed off Cape Carbonara and sunk without warning on November 8, 1915 by U-38, under the command of Kapitänleutnant Max Valentiner. [The U-38 was flying the flag of Austria-Hungary as the German Empire was not yet at war with Italy.] Of the 446 passengers and 163 crew, 206 people were lost, including 9 Americans.
The Ancona was fully booked and bound from Messina to New York under the Austrian flag. Coming as it did six months after the sinking of the Lusitania, the Ancona incident added to a growing outrage in the U.S. over unrestricted submarine warfare, and U.S. Secretary of State Robert Lansing dispatched a sternly-worded protest to Vienna.
After receiving no satisfactory response from Austro-Hungarian Foreign Minister Baron István Burián von Rajecz, in December 1915 the U.S. demanded that the Habsburg government denounce the sinking and punish the U-boat commander responsible. Germany, then concerned to maintain American neutrality, advised Burián to accede to the U.S. demands, and Vienna eventually agreed to pay an indemnity and assured Washington that the U-boat commander would be punished, although this was a meaningless promise since he was a German officer. Following the settlement of the affair, the Austro-Hungarian government requested that German submarines refrain from attacking passenger vessels while flying the Austrian flag.
Burián's diplomatic accession to U.S. demands angered Grand Admiral Anton Haus, commander of the Austro-Hungarian Navy, who had advocated taking a hard line following the sinking. Haus justified the sinking on the grounds that the Ancona could have been used on its return voyage from the U.S. to transport armaments or Italian emigrants returning home to enlist in the Italian Army. Germany's decision in April 1916 to suspend unrestricted submarine warfare terminated the debate.