Complex sentence: It was thrown into the battle on the San against the Austrian First Army, and succeeded in taking some 6,000 prisoners and nine guns, but one of their divisions was down to 900 men by 19 May.
Split into simpler sentences: It was thrown into the battle on the San against the Austrian First Army, and succeeded in taking some 6,000 prisoners and nine guns. One of their divisions was down to 900 men on 19 May.