Because its leader had been shot, Austria-Hungary declared war on Serbia. As a result: Russia got involved because Russia had an alliance with Serbia. Germany then declared war on Russia because ...

Backed up by Germany, Austria-Hungary declares war on Serbia on 28 July. Russia quickly steps in to protect the small nation and mobilises its army. Germany responds by declaring war on Russia.

The Royal Family is set to lead the nation in Remembrance Sunday commemorations at the Cenotaph this weekend, as events across Britain pay tribute to the anniversary of the First World War's ...