towards Neufchâteau and the Third Army of General Pierre Ruffey attacked towards Arlon, as a right flank guard for the Fourth army. South of Verdun, the Third Army was renamed Army of Lorraine and was to watch for a German offensive from Metz, which left the remainder of the Third Army free to concentrate on the offensive into Belgium. The French armies invaded Belgium with nine infantry corps but ten German corps and six reserve brigades of the 4th and 5th armies lay between Metz and the north of Luxembourg. The German 4th Army under Albrecht, Duke of Württemberg and 5th Army of Crown Prince Wilhelm had moved slower than the 1st, 2nd and 3rd armies and the French offensive towards them was reported on 21 August. The French armies had few maps and were unaware of the size of the German force opposite, as the Third Army brushed aside small German detachments. On 22 August in the Third army area, the V Corps attacked dug-in German troops at Longwy at in thick fog and heavy rain, with no artillery support. As the fog lifted, German artillery caught the French guns in the open and silenced them. A German counter-attack routed a French division and the corps was not rallied until the evening. To the north the IV Corps also advanced in fog and encountered German troops dug in near Virton and was forced back also with a division routed. On the southern flank, the VI Corps was pushed back a short distance. In the Fourth Army area, the II Corps on the right flank managed to keep level with the Third Army to the south but was not able to advance further. The Colonial Corps on the left was defeated at the Battle of Rossignol, south of Neufchâteau and had but the 5th Colonial Brigade on the left easily reached Neufchâteau, before it too was repulsed with many casualties. Further north, XII Corps advanced steadily but the XVII Corps beyond was outflanked and the 33rd Division lost most of its artillery. On the northern flank the XI and IX corps were not seriously engaged. The French commanders were ordered by Joffre to continue the offensive on 23 August, as early as possible since his strategy depended on the success of the Third and Fourth armies. Ruffey replied in the morning that the attack could not begin until his divisions