There was close co-operation between the British and French forces. French Commander-in-Chief Joseph Joffre worked to coordinate Allied military operations and to mount a combined Anglo-French offensive on the Western Front. The result was the great Battle of the Somme in 1916 with massive casualties on both sides and no gains. Paul Painlevé took important decisions during 1917 as France's war minister and then, for nine week's, premier. He promoted the Nivelle Offensive—which failed badly and had negative effects and its effects on the British Army. The positive result was the decision to form the Supreme War Council that led eventually to unity of command. The disasters at Passchendaele hurt Britain, its army and civil-military relations.