The assassination of Austro-Hungarian Archduke Franz Ferdinand in Sarajevo on 28 June 1914 triggered a cascade of alliance obligations that dragged all major European powers into war within weeks. Germany, as a leading member of the Central Powers alongside Austria-Hungary and the Ottoman Empire, mobilised nearly 13 million soldiers over four years of devastating industrial warfare.

Germany fought on two fronts simultaneously: the Western Front in France and Belgium, where trench warfare produced a stalemate of unprecedented carnage (the Battle of the Somme alone caused over one million casualties in 141 days), and the Eastern Front against Russia. The war at sea — including unrestricted U-boat warfare — eventually drew the United States into the conflict in April 1917. Germany's Spring Offensive of 1918 initially broke the Allied lines but was ultimately repulsed, leading to total collapse.

The Armistice of 11 November 1918 and the subsequent Treaty of Versailles (1919) imposed punishing reparations of 132 billion gold marks, stripped Germany of 13% of its territory and 10% of its population, limited its army to 100,000 men, and assigned sole "war guilt" to Germany under Article 231. These conditions created deep political resentments exploited by nationalist movements. The Weimar Republic (1919–1933) that emerged faced hyperinflation in 1923 — when a loaf of bread cost 200 billion marks — followed by the Great Depression after 1929, which sent unemployment above 30%.

Germany's unconditional surrender on 8 May 1945 — V-E Day (Victory in Europe Day) — ended six years of the most destructive war in human history, claiming an estimated 70–85 million lives worldwide. Germany itself lay in ruins: over 3.5 million German civilians had been killed by bombing, hunger, and displacement; Berlin was reduced to rubble; and over 12 million ethnic Germans were expelled from Eastern Europe in the largest forced migration in history.

The country was divided into four Allied occupation zones controlled by the USA, USSR, Britain, and France. Berlin, deep in the Soviet zone, was similarly divided. Growing tensions between the Western Allies and the Soviet Union crystallised into the Cold War. The Berlin Blockade (June 1948–May 1949), in which the Soviets cut off all land routes to West Berlin, was met by the Western Allied Berlin Airlift — 278,228 flights over 15 months delivering 2.3 million tonnes of supplies.

On 23 May 1949, the Federal Republic of Germany (FRG / West Germany) was proclaimed with Konrad Adenauer as its first Chancellor; on 7 October 1949, the German Democratic Republic (GDR / East Germany) was established under Soviet influence. West Germany joined NATO in 1955 and rebuilt rapidly into an economic powerhouse (the Wirtschaftswunder, "economic miracle"). East Germany, a one-party Socialist state under the SED, erected the Berlin Wall on 13 August 1961 to stem the flight of citizens westward — over 3.5 million had already left.

Reunified Germany rapidly became the political and economic anchor of a united Europe. As a founding member of the European Union and NATO, Germany has played a central role in European integration — from the Maastricht Treaty (1992) that created the euro, to EU enlargement into Eastern Europe. The Bundestag moved from Bonn to Berlin's rebuilt Reichstag in 1999, under Norman Foster's iconic glass dome, symbolising transparency and democratic renewal.

Germany has navigated major challenges: the Agenda 2010 labour reforms under Chancellor Gerhard Schröder (2003) restructured the welfare state and restored competitiveness; Chancellor Angela Merkel's 16-year tenure (2005–2021) saw Germany through the 2008 financial crisis, the Eurozone debt crisis, the 2015 refugee crisis — when Germany admitted over one million asylum seekers — and the COVID-19 pandemic. Germany's Energiewende (energy transition) has made it a global leader in renewable energy, with over 46% of electricity from renewables by 2023, even as the nuclear phase-out debate continues.

Today, Germany is the world's third-largest economy (GDP ~$4.5 trillion), home to global industrial giants (Volkswagen, Siemens, BASF, SAP), and a major exporter of cars, machinery, and chemicals. Its federal system of 16 Länder (states), independent judiciary, free press, and robust civil society stand as achievements built consciously on the lessons of its dark 20th-century history. The concept of Erinnerungskultur — a culture of remembrance — and Germany's frank confrontation with the Nazi past remains a model for post-conflict societies worldwide.