German invasion of Belgium

The German invasion of Belgium was the first campaign of World War I and the cause of the entry of Belgium and the United Kingdom of Great Britain and Ireland (plus her colonies) into the conflict on the side of the Allied powers of World War I.

Background
On July 28, 1914, following the assassination of Austrian archduke and heir apparent to the throne, Franz Ferdinand, the Kingdom of Austria-Hungary declared war on Serbia. This started a chain reaction of political events: Serbia's ally Russia joined the war on Austria, Austria's ally Germany joined the war on Russia and Serbia, and Russia's ally France declared war on both of the Central Powers. The Austrians and Hungarians were sidelined at the beginning of the conflict, because the Germans were the first to make their move. Their commanders agreed on initiating the Schlieffen Plan, which was a complex invasion route to defeat France and Russia. The plan was to have one force hook through neutral Belgium and enter France from the north, while another German army led a holding battle on Germany's borders. Another German army would invade Russia and capture Moscow, ending the war. This was what the Germans followed, invading the neutral and weak country of Belgium.

Invasion
Belgium had a weak fighting force of 117,000 troops, but the Belgians erected several defensive positions to keep out any invaders. The Germans invaded on August 4, declaring war on all of the Allied Powers. The 1st Army, 2nd Army, and 3rd Army were sent to invade Belgium, despite its declaration of neutrality in World War I. That same day, an advanced force of six German brigades crossed the German border and attacked the Belgian city of Liège, which was a weak city yet surrounded by a ring of fortresses. The Germans quickly seized the city, but the forts threatened the Germans' timetable. The Germans bombarded the Belgians with Big Bertha artillery and Krupp guns, but the city only fell on August 16. The real German invasion was supposed to occur on August 15, but the resistance in the city of Liège had sidetracked them. On August 18, the Germans made their real invasion, and despite the delay, the Germans were able to advance down the Meuse River and capture Namur. On August 20, the Germans under the command of Alexander von Kluck seized Brussels, forcing King Albert I of Belgium and his government to retreat to the vital port city of Antwerp, which they made their capital. It was pounded away at by German artillery and mortars, but Belgian resistance stiffened as the war turned from fighting an invading force to defending their monarch. The Germans did not subdue the defenses of the city until October 10th, 1914, when the last elements of Belgian opposition surrendered.

The stiffness of Belgian resistance and fear of guerrillas and snipers behind the lines caused the Germans to order the execution of over 670 civilians at Dinant. Further massacres and executions followed, leading to the invasion of Belgium being called the Rape of Belgium. Attempts were made after the war to excuse these barbarties, and even to suggest that they had been invented for propaganda purposes.

Aftermath
After the invasion of Belgium, the United Kingdom of Great Britain and Ireland declared war on Germany and Austria-Hungary, honouring the Treaty of London (1839). Along with Britain was Japan, South Africa, New Zealand, Australia, Rhodesia, British Raj, Canada, and several other of Britain's allies and protectorates. This was the first sign of when the war turned against Germany, as the French troops in the war were later saved by the British on various occasions, such as at the First Battle of the Marne.

Germany remained in control of Belgium until their surrender in November 1918, managing to hold onto Brussels until the end of the war. Belgium was used by the Germans as a spring-board for their invasion of northern France and their advance on the French capital of Paris, which was halted by stiff French and British resistance at the Marne. The Germans had over a million soldiers defending Belgium throughout the conflict, and most were either killed in the campaigns in France, wounded, or surrendered following the surrender of Germany. After the war ended, Albert I was reinstated as monarch and he returned to Brussels to lead his nation once more, ruling until his death in 1934.