On 23.08.1944 Major Thieme, commander of the Feld-Ersatz-Bataillon of the 11. Panzer-Division, was stationed in Montelimar. On this day he received the order to block the Grenoble-Lyon road. Reinforcing his battalion was an NCO training group (equipped with Panzer II's), the Panzer-Aufklärungs-Abteilung 11, the I./Pz.Gren.Rgt.110 and 1. Battery (self-propelled artillery). Together these units formed Kampfgruppe Thieme. His troops first engaged in combat to occupy La Coucourde and the Rhone valley, and later that day prevented an enemy thrust west of Crest.
A few days later, on 27.08.1944, Kampfgruppe Thieme was reorganized (it now contained (I./Pz.Gren.Rgt.110, 1./Pz.Pi.Btl. 201, 2 batteries of artillery and 8 Panthers). They received the new order to take Romans-sur-Isère and the local supply dump there. Thieme launched a surprise attack on the US troops stationed there and smashed them, thereby allowing the main body of the 19. Armee to withdraw through the Tain valley.
On 31.08. while reassembling his replacement battalion in Bourg en Bresse, he learned that the American had taken the bridge at Pont d'Ain. Thieme immediately gathered all available forces and recaptured the bridge from the US, and blew it up to prevent a rapid pursuit by the enemy.
On 06.09.1944 Thieme, now deputy commander of the Panzergrenadier-Regiment 111, was ordered to establish a blocking position at the pass at Pont-de-Roide (30 km south of Belfort). However he only had the I./Pz.Gren.Rgt.110 available. Being out of contact with the rest of the division, he gathered together all local Heer and Luftwaffe troops into a Kampfgruppe. With these forces he established a defensive position along the line Roches-Pont-de-Roide-Remondants, and was able to fend off US attempts to break this line. Thus the advance of the American army into the Rhine plain was prevented.
For this string of successful delaying actions Thieme was awarded the Oak Leaves to his Knight's Cross.
In the battles at the Remagen bridgehead in the timeframe 09.-19.03.1945, Thieme and his Kampfgruppe proved one of the best German units at hand. In this timeframe they were able to repeatedly bring US attacks to a halt, and inflicted losses of 22 tanks, 218 confirmed dead (plus other equipment) on the enemy. For his tenacity during this battles Thieme was recommended for the Swords.
Thieme was recommended on 10th April 1945 with support of Generalfeldmarschall Model. Although all formal routes were taken, it was not formally awarded. However due to the so called Dönitz Erlaß, this could be considered a justified awarding. The awarding therefore was accepted by the Ordensgemeinschaft der Ritterkreuzträger and the Federal German Government. According recent research (Scherzer), the awarding however would have been not official.