Immediately prior to the war's outbreak in 1914, Central Europe was dominated by two powerful states: Germany to the north and its weaker cousin, the Austro-Hungarian Empire, to the South. The two countries formed the core of the Central Powers, also known as the Quadruple Alliance because they were joined after war began by Bulgaria and the Ottoman Empire (modern Turkey). The other major pre-war alliance was the Triple Entente, a pact between Russia, Great Britain, and France (called the Allied Powers during the war). These alliances set the stage for a massive war: any dispute between two members of these blocs could pull in all of the others, as the treaties committed these states to defending their allies. And that's exactly what happened.