The 11th and 20th Hussars took part in a counter-attack in pursuit of the German Army.
On 6th September, barely a month from their mobilisation, the 20th Hussars were part of the 5th Cavalry Brigade in the counter-attack across the Marne. The Regiment led the Brigade north, crossing the Marne on the 9th September. The pursuit of the German army continued throughout 10th September with B Squadron of the 20th in the lead. But fighting on both flanks prevented a faster advance.
On 14th September, the 20th crossed the Aisne on a pontoon bridge under artillery fire. The Colonel dismounted the regiment and they led their horses on foot into the town of Vailly. Accurate and heavy German artillery fire on the infantry forward positions dictated a withdrawal across the Aisne, again under a heavy bombardment, causing casualties.
Following the advance to the River Aisne, the 11th Hussars were involved in the Battle of Messines from 12th October to 2nd November 1914.