Intelligence was declared by Clausewitz to be a source of uncertainty on the battlefield, and he advised commanders to rely on their intuition instead. It is a paradox of the Second World War that when, as never before, an abundance of intelligence was available to Allied commanders, Clausewitz's dictums still influenced some of their operational decisions. This thesis explores this duality, and how it influenced the relationship between intelligence and command at the operational level of war during the conflict. It does so through the medium of the British Army, in particular Eighth Army's operational performance - under Bernard Montgomery, Oliver Leese and Richard McCreery - at defining moments of the Italian campaign. The thesis demonstrates the ambiguity present within the British Army's doctrinal attitude towards intelligence at the operational level, which was reflected in the . tardiness with which intelligence was incorporated into the army's operational machinery during the first half of the war. That this was eventually achieved was illustrated by the general efficacy of Eighth Army's intelligence organisation in Italy, and the viability of its intelligence product. Nevertheless, the peculiarities of the Italian theatre reduced the productiveness of the chief sources of intelligence, and created occasional, but critical, gaps in the intelligence picture. This only partially explains, however, why Eighth Army's operational performance in Italy was punctuated by intelligence failure. Under Montgomery and Leese, intelligence was merely an ancillary, and often sidelined, tenet of their operational technique, and it was only under McCreery that Eighth Army practised intelligence-led warfare. These findings seriously question the historiographical belief that, by the second half of the war, the British Army had fully and unconditionally incorporated intelligence into its operational considerations, and that commanders were willing to act upon it and fashion their operational methods according to its dictates.