It had taken the 8th Army just five days to reach Primosole Bridge from the invasion area, accounting for half of the eastern coastline on the way, yet they came to an abrupt halt thereafter. German reinforcements were beginning to arrive in some strength and their defensive positions became more organised, and the terrain ahead, dominated by Mount Etna, was rugged and ideal for defensive actions. From the outset the intention of the Axis was not to drive the Allies out of Sicily, but to fight a phased withdrawal, yielding ground reluctantly and forcing their opponents to battle for every yard. All ranks of the German army were informed that they were falling back of their own volition, and this news and the success of their tactics gave them great confidence.
It was the struggle for Catania and the ground beyond that led to some fractures in the Allied leadership. General Montgomery, finding that there was no way through for his men along the eastern coastline, began a series of outflanking actions further inland in the hope of finding another route through to Messina. Whilst remaining true to the original plan, Montgomery hoped to beat the Americans to this final objective, as he would attempt to do several times during the remainder of the war. General Patton, having now secured the 7th Army's beachhead and looking at the prospects for a thrust inland, took offence at Montgomery's outflanking manoeuvres as they encroached on his own line of advance, and he felt that they were aimed at relegating the Americans to a token force, protecting the British flank while they in turn stole all the glory.
Patton responded by taking matters into his own hands and deviating from the general plan for the expansion of the Sicilian campaign. It was here that the lack of an agreed strategy and close control on behalf of General Alexander and his 15th Army Group began to tell. Montgomery had broadly intended to push the 8th Army north along the eastern coastline and, as he had achieved, pin down the majority of the Axis forces on his front. Patton was then to drive the 7th Army along his left flank, cut Sicily in two, and then move to capture Messina and trap the enemy opposing the 8th Army. Patton continued to make moves in this direction, despite having been unceremoniously shunted off this course by the British, but he also ordered a significant part of his strength to move into the less important areas of western Sicily.
The major prize in the west was Palermo, the Sicilian capital, the fall of which would not only win the 7th Army great renown, but it would also give Patton a major port that would keep his men more effectively supplied for actions on the northern coast. On the 17th July, Alexander gave his consent for what he thought was a "reconnaissance" in this direction, but he later countermanded these orders when he began to sense that Patton was concentrating too much of his energies in western Sicily. Patton, however, ignored the message and sent back to the 15th Army Group that their transmission had been unintelligible. By the time confirmation of the order was received, the 7th Army was within sight of Palermo. Its capture, on the 22nd July, was a great publicity coup for Patton and his men, though in military terms it had achieved little: western Sicily was defended only by Italians who had quickly surrendered, meanwhile the main focus of the campaign, Messina, was slipping away.
Nevertheless, Patton thereafter put all his energies into a drive on Messina, which the 8th Army was still attacking towards, though again his chief concern was more to beat the British to it rather than to defeat the Germans. Progress on both fronts was reduced to a crawl, with the four German divisions in Sicily, assisted by further Italian formations, skilfully exploiting the mountainous terrain to ensure that the Allies would have no easy victory. The fighting was hard, therefore, and even when the British and Americans finally broke through on their respective fronts, the few roads beyond were so heavily mined and protected by rearguards that the advance still progressed at a snail's pace. On the 11th August, the Axis made the decision to begin the evacuation of their forces from Sicily, and although they were closely followed by the 7th and 8th Armies, neither of them were able to move quickly enough to overtake them. On the 17th August, the 7th Army won the race to Messina, entering it just hours after the last Axis troops had withdrawn across the straits to mainland Italy; the advance guard of the 8th Army arrived a few hours later.