The 1910s (pronounced "nineteen-tens", also abbreviated as the "teens") was a decade of the Gregorian calendar that began on January 1, 1910, and ended on December 31, 1919. The 1910s represented the culmination of European militarism which had its beginnings during the second half of the 19th century. The conservative lifestyles during the first half of the decade, as well as the legacy of military alliances, was forever changed by the assassination, on June 28, 1914, of Archduke Franz Ferdinand, the heir presumptive to the Austro-Hungarian throne. The murder triggered a chain of events in which, within 33 days, World War I broke out in Europe on August 1, 1914. The conflict dragged on until a truce was declared on November 11, 1918, leading to the controversial, one-sided Treaty of Versailles, which was signed on June 28, 1919.
The war's end triggered the abdication of various monarchies and the collapse of five of the last modern empires of Russia, Germany, China, Ottoman Turkey and Austria-Hungary, with the latter splintered into Austria, Hungary, southern Poland (who acquired most of their land in a war with Soviet Russia), Czechoslovakia and Yugoslavia, as well as the unification of Romania with Transylvania and Moldavia. However, each of these states (with the possible exception of Yugoslavia) had large German and Hungarian minorities, there creating some unexpected problems that would be brought to light in the next two decades. (See Dissolution of Austro-Hungarian Empire: Successor States for better description of composition of names of successor countries/states following the splinter.)