The German 2nd Army commander General Karl von Bülow had ordered a rapid pursuit after the battles of 21–24 August against the French Fifth Army and the British Expeditionary Force (BEF). The 1st and 2nd armies were sent to the south-west to gain the left flank of the Allied line. After encountering "especially obstinate" resistance at Marbaix and Le Grand-Fayt, the X Reserve Corps had been ordered to continue its advance to the south-west. The 2nd Royal Munster Fusiliers, had been ordered to hold its ground at all costs, in their first action in France. Less than a battalion strength, just 3 companies of the 2nd. Battalion of The Munsters supported by a couple of field guns halted the advance of the German Army for fourteen hours in the area of Oisny and Étreux during the retreat from Mons on August 27.
Under continual pressure from German attacks, the Munsters fell back to an orchard near the village of Étreux. As night fell on the evening of the 27 August, the Munsters found themselves surrounded on all sides by the German army. Having exhausted their ammunition, they had no other option but to surrender. In their action at Ètreux, only four officers and 240 other ranks of the 2nd Munsters survived but the battalion prevented German pursuit of I Corps, gaining time for the BEF to escape. The 2nd Munsters were outnumbered at odds of over 6:1 and when finally defeated, the survivors were congratulated on their supreme bravery by the German soldiers they had fought. The X Reserve Corps had continued its advance towards Wassigny and Étreux on 27 August, where the 19th Reserve Division reported that it had "scattered a British battalion".
Bowman, T. (2003). Irish Regiments in the Great War: Regular Regiments at War. Manchester: Manchester University Press. ISBN0-7190-6285-3.
Humphries, M. O.; Maker, J. (2013). Der Weltkrieg: 1914 The Battle of the Frontiers and Pursuit to the Marne. Germany's Western Front: Translations from the German Official History of the Great War I. Part 1. Waterloo, Canada: Wilfrid Laurier University Press. ISBN978-1-55458-373-7.