Before the outbreak of World War I, Belgium relied on supplies of imports for almost three-quarters of all food consumed. With the German invasion in August 1914, the importation ceased and, as the economic crisis created by the invasion escalated, the distribution of the food that was available began to break down. In particular, the British Royal Navy began a four-year "Blockade of Europe" which, although aimed at Germany, also cut food supplies from neutral countries to German-occupied Belgium.