WHAT ALL HAPPENED APRIL TO MAY 1915
Find out what all happened April to May 1915

French pilot Roland Garros is shot down and glides to a landing on the German side of the lines during World War I. (18. April 1915)

Lassen Peak erupts with a powerful force, and is the only mountain other than Mount St. Helens to erupt in the contiguous US during the 20th century. (22. May 1915)

World War I: German submarine U-20 sinks RMS Lusitania, killing 1,198 people including 128 Americans. Public reaction to the sinking turns many formerly pro-Germans in the United States against the German Empire (7. May 1915)

The last British Liberal Party government (led by Herbert Henry Asquith) falls. (17. May 1915)

The arrest of 250 Armenian intellectuals and community leaders in Istanbul marks the beginning of the Armenian Genocide. (24. April 1915)

World War I: Italy declares war on Austria-Hungary. (24. May 1915)

Japanese 21 Demands Ultimatum to China (Commemorated as National Day of Humiliation) (7. May 1915)

World War I: The Battle of Gallipoli begins—The invasion of the Turkish Gallipoli Peninsula by Australian, British, French and New Zealand troops begins with landings at Anzac Cove and Cape Helles. (25. April 1915)

The RMS Lusitania departs from New York City on her two hundred and second, and final, crossing of the North Atlantic. Six days later, the ship is torpedoed off the coast of Ireland with the loss of 1,198 lives, including 128 Americans, rousing American sentiment against Germany. (1. May 1915)

Three trains collide in the Quintinshill rail disaster near Gretna Green, Scotland, killing 227 people and injuring 246; the accident is found to be the result of non-standard operating practices during a shift change at a busy junction. (22. May 1915)

The use of poison gas in World War I escalates when chlorine gas is released as a chemical weapon in the Second Battle of Ypres. (22. April 1915)

World War I: Second Battle of Artois between German and French forces. (9. May 1915)

World War I: Italy joins the Allies after they declare war on Austria-Hungary. (23. May 1915)