While the Battle of Verdun ground on, the Allies built up resources for major offensives on the Eastern Front under General Brusilov and a coordinated Anglo-French offensive astride the River Somme. At sea the German High Seas Fleet sought a conclusive engagement in the North Sea. Thus came about ‘Der Tag’ – the culmination of the Dreadnought Arms Race – fought off Jutland on 31 May 1916.