The Battle of Messines was an attack by the British Second Army, on the Western Front, near the village of Messines in West Flanders, Belgium, during the First World War. The Nivelle Offensive in April and May had failed to achieve its more grandiose aims, had led to the demoralisation of French troops and confounded the Anglo-French strategy for 1917. The attack forced the Germans to move reserves to Flanders from the Arras and Aisne fronts, relieving pressure on the French.

The Second Battle of the Aisne was the main part of the Nivelle Offensive, a Franco-British attempt to inflict a decisive defeat on the German armies in France. The Entente strategy was to conduct offensives from north to south, beginning with an attack by the British Expeditionary Force (BEF) then the main attack by two French army groups on the Aisne. General Robert Nivelle planned the offensive in December 1916, after he replaced Joseph Joffre as Commander-in-Chief of the French Army.