All these troops constituted the 1st German Army, which was directed against the French 6th Army on the Ourcq, and the British forces, and the left of the 5th French Army south of the Marne. The 2nd German Army (IX., X., X.R. and Guard) was moving against the centre and right of the 5th French Army and the 9th French Army. On Sept. 7 both the 5th and 6th French Armies were heavily engaged on our flank. The 2nd and 4th Reserve German Corps on the Ourcq vigorously opposed the advance of the French towards that river, but did not prevent the 6th Army from gaining some headway, the Germans themselves suffering serious losses. The French 5th Army threw the enemy back to the line of the Petit Morin River, after inflicting severe losses upon them, especially about Montceaux, which was carried at the point of the bayonet. The enemy retreated before our advance, covered by his 2nd and 9th and Guard Cavalry Divisions, which suffered severely. Our cavalry acted with great vigour, especially General De Lisle's Brigade, with the 9th Lancers and 18th Hussars. On Sept. 8 the enemy continued his retreat northward, and our army was successfully engaged during the day with strong rearguards of all arms on the Petit Morin River, thereby materially assisting the progress of the French armies on our right and left, against whom the enemy was making his greatest efforts. On both sides the enemy was thrown back with very heavy loss. The First Army Corps encountered stubborn resistance at La Trétoire (north of Rebais). The enemy occupied a strong position with infantry and guns on the northern bank of the Petit Morin River; they were dislodged with considerable loss. Several machine guns and many prisoners were captured, and upwards of 200 German dead were left on the ground. The forcing of the Petit Morin at this point was much assisted by the cavalry and the 1st Division, which crossed higher up the stream. Later in the day a counter attack by the enemy was well repulsed by the First Army Corps, a great many prisoners and some guns again falling into our hands. On this day (Sept. 8) the Second Army Corps encountered considerable opposition, but drove back the enemy at all points with great loss, making considerable captures. The Third Army Corps also drove back considerable bodies of the enemy's infantry and made some captures. On Sept. 9 the First and Second Army Corps forced the passage of the Marne and advanced some miles to the north of it. The Third Corps encountered considerable opposition, as the bridge at La Ferté was destroyed and the enemy held the town on the opposite bank in some strength, and thence persistently obstructed the construction of a bridge; so the passage was not effected until after nightfall. During the day's pursuit the enemy suffered heavy loss in killed and wounded, some hundreds of prisoners fell into our hands, and a battery of eight machine guns was captured by the 2nd Division.