At the beginning of the First Battle of the Isonzo on 23 June 1915, Italian forces outnumbered the Austrians three-to-one but failed to penetrate the strong Austro-Hungarian defensive lines in the highlands of northwestern Gorizia and Gradisca. Because the Austrian forces occupied higher ground, Italians conducted difficult offensives while climbing. The Italian forces therefore failed to drive much beyond the river, and the battle ended on 7 July 1915.