What is the third army in World War 2?

Answer 1

The "Third Army" usually denotes a field army. A number of countries have had a Third Army, including Germany. The German Third Army was disbanded in November 1939, only five weeks after the end of the Polish campaign, in which it took part.

Since you asked this in the "Battle of the Bulge" category I am guessing you are asking about the Third US Army. A field army, such as the 3rd, has in it two or more Corps. Each Corps has in it two or more divisions. After the landings at Normandy in France in 1944, the Allied field armies from north to south were the Canadian First Army, British Second Army (together these were the 21st Army Group), the 9th, 1st, and 3rd US Armies (together these three were the 12th Army Group) and the 7th US Army and the French 1st Army (together these were the 6th Army Group). The German attack in the Ardennes Offensive ("Battle of the Bulge") hit the Allied line at the boundary of the US 9th and 1st Armies.

The German attack broke through the Allied line. But the German plan was a desperate one, and for continued success depended on capturing enough Allied gasoline to keep the German tanks moving.

The Third US Army was south of this breakthrough, aimed generally eastward toward the German border. At this time the 3rd Army consisted of the US VIII, XII and XX Corps. The commanding general of the US 3rd Army was General George S. Patton, Jr. He may have been the best US field army commander of the war. The Germans thought so, anyway. Within a day or two Patton halted his attacks eastward, reoriented his army to face northward, and attacked into the soutern flank of the German penetration. The goal may have been to cut off the Germans who had broken through, or to at least restore the Allied line and push the Germans back out, while relieving isolated units which continued to hold out, though surrounded by the Germans.