Sector Hibernia was a section of the Vosges battlefront on the Western Front of World War I which saw heavy fighting between the Entente and German forces during the spring of 1918.
An Allied force consisting primarily of British troops (the 59th Division, the Hertfordshire Regiment, and the Royal Inniskilling Fusiliers) and contingents of French troops from the 17th and 217th Regiments and US troops from the 33rd Infantry Division and the 5th Marine Regiment found themselves under attack from five Imperial German Army infantry regiments (three of them reservists), two battalions of sturmtruppen, and a battalion of Lower Silesian pioniers, who charged across the typically-quiet Vosges forest and assaulted the Allied trench. The Entente forces held back the German assault before launching their own assault on the German positions. The Germans were much better defenders than attackers, and they succeeded in repulsing the Allied attack after much effort; the Allied troops, overwhelmed by large numbers of German reinforcements, were forced to retreat back to their starting positions. There, they repelled a German counterattack, which was also conducted with great vigor. The Entente forces launched one final counterattack, having already expended much of their energy, and their final attack succeeded in capturing the German trench and forcing the Germans to retreat into the forest. With the German trench in Entente hands, the battle was an Allied victory, although 1,635 soldiers died for relatively little gain for either side.