Mobilisation

Before 1914 the continental great powers relied on universal military service: in peacetime only part of each year's conscripts were under arms and the rest formed the reserve. Mobilisation plans built on the timetables of thousands of trains were so rigid that they were hard to change or halt, and the German war plan required an immediate attack in the west. So the mobilisation of one state set off the mobilisation of its neighbours.

In July 1914, after Serbia mobilised and Austria-Hungary partially mobilised, the Tsar ordered general mobilisation on 30 July, Austria-Hungary followed on 31 July, and Germany and France on 1 August. Within days millions of men were under arms. In the Polish lands the mobilisation of the three partitioning powers called Poles into the Russian, German and Austro-Hungarian armies, which fought one another.