The Allies assembled another army and planned for a summer offensive. The combatant Coldstream companies had been garrisoned in Brussels and Ath, where they were joined by the 2nd Battalion's remaining four companies in early 1815. In preparation for the coming offensive, Graham's battalion joined with the 2nd Battalion of the Scots Guards to form the 1st Division's 2nd Brigade. Basing themselves in Belgium, the Allies formed two armies, with the Duke of Wellington commanding the Anglo-Allies, and Gebhard Leberecht von Blücher commanding the Prussians. Napoleon marched swiftly through France to meet them, and split his army to launch a two-pronged attack. On 16 June 1815, Napoleon himself led men against Blücher at Ligny, while Marshall Ney commanded an attack against Wellington's forward army at the Battle of Quatre Bras.