In January 1943, the German-Italian Panzer Army (Deutsch-Italienische Panzerarmee) under command of Erwin Rommel (also known as Desert Fox) had retreated to the Mareth Line, originally a French line of defensive fortifications near the coastal town of Medenine in southern Tunisia.
When Rommel left Tunisia in March 1943, after the failed attack at Medenine (Operation Capri), Bayerlein was appointed German liaison officer under the new commander, Giovanni Messe: in practice, Bayerlein acted as he saw fit, disregarding the Italian's orders.