The 2nd Dublins arrived in France in the month war was declared as part of the 10th Brigade in the 4th Division. The Division was part of the British Expeditionary Force (BEF), the professionals of the old regular army, known as the 'Old Contemptibles' after a comment made by the German Kaiser. The 2nd Dublins took part in the retreat following the Battle of Mons, taking part in their first engagement on 26 August 1914 at Le Cateau that helped delay the German advance towards Paris, inflicting such heavy casualties that the Germans thought they faced more machine-guns than they actually did. The BEF then resumed their retreat, but many men, including from the Dublin Fusiliers, were stranded behind German lines, and many were taken prisoner by the Germans. The Battalion, badly depleted, later took part in the Battle of the Marne (5–9 September) that finally halted the German advance just on the outskirts of Paris, forcing the Germans to retreat to the Aisne. There, the 2nd Dublins took part in the Battle of the Aisne and later took part in their last major engagement of the war, at the Battle of Messines, which began on 12 October and ended on 2 November.