The main part of French Expeditionary Corps in Italy which had been fighting there was withdrawn from the Italian front, and added to the French First Army—under General Jean de Lattre de Tassigny—and joined the US 7th Army to form the US 6th Army Group. That was the force that conducted Operation Dragoon (also known as Operation Anvil), the Allied invasion of southern France. The objective of the French 2nd Corps was to capture ports at Toulon (France's largest naval port) and Marseilles (France's largest commercial port) in order to secure a vital supply line for the incoming troops. Most of the German troops there were second-line, consisting mainly of static and occupation units with a large number of "Osttruppen" volunteers, and with a single armoured division, the "11. Panzer-Division". The Allies sustained only relatively light casualties during the amphibious assault, and were soon in an all-out pursuit of a German army in full retreat along the Rhône valley and the Route Napoleon. Within 12 days the French forces were able to secure both ports, destroying two German Divisions in the process. Then on 12 September, French forces were able to connect to General George Patton's Third Army. Toulon and Marseille were soon providing supplies not only to the 6th Army Group but also to General Omar Bradley's 12th Army Group, which included Patton's Army. For its part, troops from de Lattre's French First Army were the first Allied troops to reach the Rhine.