At the eastern edge of the 4th Italian Army sector, the Croda Rossa di Sesto was occupied by Austro-Hungarian troops on the Sesto side. From here they could control the pass of Monte Croce di Comelico, Cima Undici, the Zsigmondy crest and . The Austrians had one of the best guides in the area, , and, from July, support from the German Alpenkorps who hoisted two mountain guns onto the northern slope of the summit, to strike at a possible Italian advance from the Monte Croce pass. Nevertheless the early months of the war were calm, mainly because snow made the peaks above 3,000m impassible.: On 7 July Italian artillery destroyed the , and in August Italian troops occupied the upper Fiscalina valley, pushing up to the Zsigmondy ridge. Despite enormous difficulties they succeeded in taking the 3,042m summit of Monte Popera. Their attention then shifted towards the Sentinella Pass.: