On 7 June 1917, the British Second Army launched its attack on Messines Ridge, detonating 19 giant mines beneath the German front-line positions. By the end of the day, one of the strongest positions on the Western Front had fallen, a place of such importance that the Germans had pledged to hold it at any cost. It was the greatest British victory in three years of war. The first two years of the First World War had represented an almost unending catalogue of disaster for the Australians. Messines was not only their first real victory, it was also the first test in senior command for Major General John Monash who commanded the newly formed 3rd Division and would later be hailed as Australia's greatest soldier. Messines was a baptism of fire for the 3rd Division which came into the line alongside the battle-scarred 4th Australian Division, badly mauled at Bullecourt just six weeks earlier in one of the worst defeats of the war. The fighting at Messines would descend into unimaginable savagery, a lethal and sometimes hand-to- hand affair of bayonets, clubs, bombs and incessant machine- gun fire, described by one Australian as '72 hours of Hell'. After their string of bloody defeats over 1915 and 1916, Messines would be the ultimate test for the Australians.