Between 1915 and 1917 there were several offensives along this front. The attacks employed massive artillery bombardments and massed infantry advances. Entrenchments, machine gun emplacements, barbed wire and artillery repeatedly inflicted severe casualties during attacks and counter-attacks and no significant advances were made. Among the most costly of these offensives were the Battle of Verdun, in 1916, with a combined 700,000 casualties (estimated), the Battle of the Somme, also in 1916, with more than a million casualties (estimated), and the Battle of Passchendaele (Third Battle of Ypres), in 1917, with 487,000 casualties (estimated).