During May, small Grenz infantry forces heroically defended the mountain passes during the Battle of Tarvis. At Malborghetto Valbruna, 400 soldiers held a blockhouse against 15,000 Frenchmen between 15 and 17 May and only 50 men survived. The French admitted only 80 casualties. At the Predil Pass blockhouse, 250 Austrians and 8 cannon held off 8,500 French soldiers for three days. On 18 May, when the position was finally overrun, the Grenzers were killed to a man. The French admitted suffering 450 casualties. At Tarvisio (Tarvis) itself, Eugène inflicted a serious defeat on Albert Gyulai's outnumbered division.