Gneisenau
Although Ludendorff had intended Blücher-Yorck to be a prelude to a decisive offensive (Hagen) to defeat the British forces further north, he made the error of reinforcing merely tactical success by moving reserves from Flanders to the Aisne, whereas Foch and Haig did not overcommit reserves to the Aisne. Ludendorff sought to extend Blücher-Yorck westwards with Operation Gneisenau, intending to draw yet more Allied reserves south, widen the German salient and link with the German salient at Amiens.
The French had been warned of this attack (the Battle of Matz (French: Bataille du Matz)) by information from German prisoners, and their defence in depth reduced the impact of the artillery bombardment on 9 June. Nonetheless, the German advance (consisting of 21 divisions attacking over a 23 mi (37 km) front) along the Matz River was impressive, resulting in an advance of 9 miles (14 km) despite fierce French and American resistance. At Compiègne, a sudden French counter-attack on 11 June, by four divisions and 150 tanks (under General Charles Mangin) with no preliminary bombardment, caught the Germans by surprise and halted their advance. Gneisenau was called off the following day.
Losses were approximately 35,000 Allied and 30,000 German.
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