On August 3, 1914, Germany declared war on France...

The war began with Austria-Hungary opening fire on Serbia on July 28. The UK entered the war on August 4.

Stephen Evans on 'World War One: Germany's forgotten war' (BBC):

A book by Christopher Clark, an Australian historian based at Cambridge University, has become a run-away best-seller in its German translation. The Sleep-walkers analyses the run-up to the war and paints a picture of blunders and misunderstandings in the complexities of European imperial politics.

Norman Stone in the Evening Standard:

The First World War was part of the great question of British foreign policy since about 1840: Germany or Russia? The British opted for Russia in 1914, as they did again in 1941.

Martin Kettle in the Guardian:

In Britain the commemoration at the Imperial War Museum is fundamentally about Britain and British people. Step into the new galleries and you find yourself watching newsreel film about the people of Britain in 1914. In Berlin the commemoration is fundamentally about Europe and the wider world. Step into that gallery and you find yourself watching newsreel film from Berlin, Vienna, Paris and St Petersburg.

Deutsche Welle's WWI page (in English).

Spiegel International's WWI page (in English).

WWI pictures at the Atlantic.