1915

WWI: British Royal Navy battleship HMS Formidable is sunk off Lyme Regis, Dorset, England, by an Imperial German Navy U-boat, with the loss of 547 crew.

WWI: German Zeppelins bomb the coastal towns of Great Yarmouth and King's Lynn in England for the first time, killing more than 20.

February – While working as a cook at New York's Sloane Hospital for Women under an assumed name, "Typhoid Mary" (an asymptomatic carrier of typhoid fever) infects 25 people, and is placed in quarantine for life on March 27.

WWI: British armed merchantman HMS Bayano (1914) is sunk in the North Channel off the coast of Scotland by Imperial German Navy U-boat SM U-27. Around 200 crew are lost, a number of bodies being washed up on the Isle of Man, with only 26 saved.

The first Roman Catholic liturgy at the newly consecrated Cathedral of Saint Paul, Minnesota, is celebrated by Archbishop John Ireland.

Imperial Trans-Antarctic Expedition: SY Aurora's drift – The SY Aurora breaks loose from its anchorage during a gale, beginning a 312-day ordeal.

China agrees to the Twenty-One Demands of the Japanese.

Women's Institutes are established in Britain.

The McMahon–Hussein Correspondence between Hussein bin Ali, Sharif of Mecca and the British official Henry McMahon concerning the Arab revolt against the Ottoman Empire begins; in exchange for assistance against the Ottomans, the British offer bin Ali their recognition of an independent Arab kingdom, although clear terms are never agreed.

WWI: A Zeppelin raid destroys No. 61 Farringdon Road, London; the premises are rebuilt in 1917, and called The Zeppelin Building.

Mexican Revolution: The U.S. recognizes the Mexican government of Venustiano Carranza de facto (not de jure until 1917).

Albert Einstein presents part of his theory of general relativity to the Prussian Academy of Sciences.