The Battle of Mons took place as part of the Battle of the Frontiers, in which the advancing German armies clashed with the advancing Allied armies along the Franco-Belgian and Franco-German borders. The British position on the French flank meant that it stood in the path of the German 1st Army. The British reached Mons on 22 August 1914 and at the time, the French Fifth Army, located on the right of the British, was heavily engaged with the German 2nd and 3rd armies at the Battle of Charleroi. The British agreed to hold the line of the Condé–Mons–Charleroi Canal for twenty-four hours, to prevent the advancing German 1st Army from threatening the French left flank. The British thus spent the day digging in along the canal.