Although the German armies were victorious in the Battle of the Frontiers their advance was brought to a halt at First Battle of the Marne. Communications between OHL and the front line broke down and Hentsch was dispatched by Moltke to the Headquarters of the First and Second Armies to assess the situation. After discovering the Armies were separated from each other by a gap of twenty-five miles and in danger of being encircled, Hentsch ordered a retreat to the Aisne.