the initial attack, the First Army widened the attack by another with the Second Battle of Arras of 1918. Bapaume fell on 29 August (during the Second Battle of Bapaume). Advance to the Hindenburg Line With the front line broken, a number of battles took place as the Allies forced the Germans back to the Hindenburg Line. East of Amiens (after the Battle of Amiens), with artillery brought forward and munitions replenished, the Fourth Army also resumed its advance, with the Australian Corps crossing the Somme River on the night of 31 August, breaking the German lines during the Battle of Mont Saint-Quentin. On 26 August, to the north of the Somme, the First Army widened the attack by another with the Second Battle of Arras of 1918, which includes the Battle of the Scarpe (1918) (26 August) and the Battle of Drocourt-Queant Line (2 September). South of the BEF, the French First Army approached the Hindenburg Line on the outskirts of St. Quentin during the Battle of Savy-Dallon (10 September), and the French Tenth Army approached the Hindenburg Line near Laon during the Battle of Vauxaillon (14 September). The British Fourth Army approached the Hindenburg Line along the St Quentin Canal, during the Battle of Épehy (18 September). By 2 September, the Germans had been forced back close to the Hindenburg Line from which they had launched their offensive in the spring. Battles of the Hindenburg Line Foch planned a series of concentric attacks on the German lines in France (sometimes referred to as the Grand Offensive), with the various axes of advance designed to cut German lateral communications, intending that the success of an attack would enable the entire front line to be advanced. The main German defences were anchored on the Hindenburg Line, a series of defensive fortifications stretching from Cerny on the Aisne river to Arras. Before Foch's main offensive was launched, the remaining German salients west and east of the line were crushed at Havrincourt and St Mihiel on 12 September and at the Battle of Épehy and the Battle of the Canal du Nord on 27 September. The first attack of the Grand Offensive was launched on 26 September by the French and the AEF in the Meuse-Argonne Offensive (this offensive includes the battles of Somme-Py, Saint-Thierry, Montfaucon, and Chesne of 1 November). On 28 September, the Army Group under Albert I of Belgium