In case of what country's attack was the origins of the Central Powers?
Central Powers The Central Powers (German: "Mittelmächte" ; Hungarian: "Központi hatalmak" ; Turkish: "İttifak Devletleri" or "Bağlaşma Devletleri" ; Bulgarian: Централни сили "Tsentralni sili" ), consisting of Germany, Austria-Hungary , the Ottoman Empire and Bulgaria – hence also known as the Quadruple Alliance (German: "Vierbund" ) – was one of the two main factions during World War I (1914–18). It faced and was defeated by the Allied Powers that had formed around the Triple Entente. The Powers' origin was the alliance of Germany and Austria-Hungary in 1879. The Ottoman Empire and Bulgaria did not join until after World War I had begun, although the Ottoman Empire retained close relations with both Germany and Austria-Hungary since the beginning of the 20th century.
Western Allied invasion of Germany The Western Allied invasion of Germany was coordinated by the Western Allies during the final months of hostilities in the European theatre of World War II. The Allied invasion of Germany started with the Western Allies crossing the Rhine River in March 1945 before fanning out and overrunning all of western Germany from the Baltic in the north to Austria in the south before the Germans surrendered on 8 May 1945. This is known as the "Central Europe Campaign" in United States military histories.