In response to pleas from the French, the Russian Army undertakes an invasion of East Prussia in the hope of taking some of the pressure off of France.

The failure of the French counteroffensive has the Allies in retreat across the front, and it now appears there is no stopping the Germans short of Paris.

The Great War started as a conflict between Austria and Serbia. Now, amid all the other conflicts emerging as the war goes continental, Austria makes its bid to punish Serbia for the assassination of the Archduke Ferdinand.

The French plan to respond to a German offensive was a counteroffensive into the German center. The French attempted this on August 21-23; it was an utter failure.

The outbreak of the Great War saw one of the German Navy's newest and most powerful battlecruisers in the Mediterranean. She was a threat to the Entente and had to be stopped. Only...what exactly is she trying to do?

The German war plan called for a massive offensive against France that would pass through Belgium, but one of the big unknowns in German war planning was whether the Belgians would resist, and if so, how fiercely.

French strategists emphasized the importance of offense and planned to respond to a German invasion with an offensive of their own. British strategy increasingly revolved around joining with France in a ground war.

A look at how Germany and Russia planned to fight the Great War.

A survey of the most important reasons why the Great War happened and why the international order failed to prevent it.

Germany mobilizes and declares war on Russia and France. As German troops move into Luxembourg and Belgium, the British Cabinet comes around and joins the war.