On Saturday, August 22, 1914, Von Buelow attacked Charleroi in full strength.  As we have seen, he had already practically settled with Namur.  Their main assault on Saturday was delivered on the Sambre bridges at Chatelet and Thuin, below and above Charleroi, respectively.  Sometime on Saturday they succeeded in crossing to turn Charleroi into one of the most frightful street battle grounds in history.  The conflict raged for the possession of iron foundries, glass works, and other factories.  The thoroughfares were swept by storms of machine-gun fire.  Tall chimneys toppled over and crashed to the ground, burying defenders grouped near under piles of debris.  Desperate hand-to-hand encounters took place in workshops, electric-power stations, and manufacturing plants.  The normal whir of machinery, now silent, was succeeded by the crack and spitting of continuous rifle fire.

The French-Turco and Zouave troops fought with savage ferocity, with gleaming eyes, using bayonets and knives to contest alleys and passageways.  House doors were battered in to reach those firing from upper windows.  Roofs and yard walls were scaled in chase of fleeing parties.  The Germans were driven out of Charleroi several times, only to return in stronger force.  Similarly with the French.  With each change of victors, the losing side turned to bombard with a torrent of artillery shells the war-engulfed city.

At nightfall on August 22, 1914, Charleroi burst into flames.  A dread and significant glow fell upon the sky.  Absent were the usual intermittent flare of blast furnaces.  The greater part of Charleroi had become a heap of ruins.  Those of its citizens still alive cowered in holes or corners for shelter.

The battle of Charleroi went on throughout the night.  Early on the morning of Sunday, August 23, 1914, Von Hausen swept down through the gap between the armies of Von Buelow and the Duke of Wuerttemberg.  He crossed the Meuse, drove from before him the French detachments watching it, and advanced to attack the rear of the French right.

Von Hausen took the French at Charleroi completely by surprise.  At the moment they could comprehend neither where he came from nor the measure of his strength.  But he was in army force.

The French were compelled to withdraw their right from Charleroi.  Von Hausen seized the advantage to hurl his forces upon their rear, while Von Buelow thundered in assault more vigorously than ever on the French front.  A powerful force was hurled upon them from an unexpected direction.  Presently the retreat of the French Fifth Army was threatened by the two Saxon corps of Von Hausen’s army, pressing on the French right flank and rear.  In this emergency the retirement of the French Fifth Army appears to have been undertaken with spontaneous realization of utmost danger.  It gave way before the attacks of Von Buelow and Von Hausen to move southward, leaving their British left wing without information of defeat.