The battle of Mons was the first major  battle fought by the British Expeditionary Force (BEF). The BEF had advanced along a 20 mile front along the Mons canal, and were on there left flank of the French 5th army.  But when the French army had been defeated at the Battle of the Sambre on the 22nd August . The British  commander Sir John French agreed to hold his position until the morning of the 23rd.   the  BEF were attacked by the German first Army . The German infantry advance was repelled by the  British infantry. and sustained  very large losses and th4e British lost 1600 killed or wounded.  But with the French forces retreating the British forces had no alternative but to retreat also. and on the morning of the 24th August they began retreating to the outskirts of Paris over a fourteen day period.

Retreat From Mons by Lady Butler  Showing the Royal Horse Guards during world war one.