At the turn of the 20th century there had been no war between any of the six great powers in Europe since 1871. There had been disputes, but no military mobilization by the powers. The balance of power was thought of as a natural leveller: if any one power became too strong then a slight shift in alignment between the others would safely restore the balance. This train of thought was put to the test in July 1914, which ultimately started the timetable to mobilisation.
Following the assassination of the Arch Duke Franz Ferdinand, Austria mobilised her forces on 25 July, as they were expecting the Serbian Government to reject their ultimatum. Serbia (formerly known as Servia) mobilised by 27 July, having rejected most of the points in the ultimatum.