to operate from airfields in Central and Southern Greece, but few planes could be diverted to the theatre. The British forces were near to fully motorised, but their equipment was more suited to desert warfare than to Greece's steep mountain roads. They were short of tanks and anti-aircraft guns and the lines of communication across the Mediterranean were vulnerable, because each convoy had to pass close to Axis-held islands in the Aegean; despite the British Royal Navy's domination of the Aegean Sea. These logistical problems were aggravated by the limited availability of shipping and Greek port capacity. The German Twelfth Army—under the command of Field Marshal Wilhelm List—was charged with the execution of Operation Marita. His army was composed of six units: First Panzer Group, under the command of General Ewald von Kleist. XL Panzer Corps, under Lieutenant General Georg Stumme. XVIII Mountain Corps, under Lieutenant General Franz Böhme. XXX Infantry Corps, under Lieutenant General Otto Hartmann. L Infantry Corps, under Lieutenant General Georg Lindemann. 16th Panzer Division, deployed behind the Turkish-Bulgarian border to support the Bulgarian forces in case of a Turkish attack. German plan of attack and assembly The German plan of attack was influenced by their army's experiences during the Battle of France. Their strategy was to create a diversion through the campaign in Albania, thus stripping the Hellenic Army of manpower for the defence of their Yugoslavian and Bulgarian borders. By driving armoured wedges through the weakest links of the defence chain, penetrating Allied territory would not require substantial armour behind an infantry advance. Once Southern Yugoslavia was overrun by German armour, the Metaxas Line could be outflanked by highly mobile forces thrusting southward from Yugoslavia. Thus, possession of Monastir and the Axios valley leading to Thessaloniki became essential for such an outflanking maneuver. The Yugoslav coup d'état led to a sudden change in the plan of attack and confronted the Twelfth Army with a number of difficult problems. According to the 28 March Directive No. 25, the Twelfth Army was to create a mobile task force to attack via Niš toward Belgrade. With only nine days left before their final deployment, every hour became valuable and each fresh assembly of troops took time to mobilise. By the evening of 5 April, the forces intended to enter southern Yugoslavia and Greece had been assembled. German invasion Thrust across southern Yugoslavia and the drive to Thessaloniki At