The image of a tank crawling across a shell-cratered battlefield remains one of the iconic representations of the Great War. Yet, despite the huge amount of attention tanks received - both at the time and from later historians - fierce debate continues to rage regarding their actual impact on the war. Neither contemporaries nor historians agree on whether the British army every really understood the potential of this new weapon and how best to integrate it into the wider army. Focusing on operations planned and executed during the war, this study challenges perceptions of senior commanders of the British Expeditionary Force as unimaginative and unresponsive to technological innovation. Instead, it demonstrates how they employed a continuous cycle of operational analysis and evaluation to create, revise and refine theories of tank co-operation with other arms. Indeed, field commanders were often enthusiastic supporters of the tank, and several attempted innovative offensive operations using them. However, without prior knowledge of the combat performance of such new technology, it was inevitable that much trial and error would be involved in finding the strengths and weaknesses of these vehicles. Whilst accepting that more could perhaps have been done before 1918 to facilitate the tank's integration into the British forces, Dr Hammond clearly demonstrates that the extreme conditions under which tank crews worked and the technological limitations of the early tanks posed severe constraints on the development of a workable 'tank doctrine'. Nevertheless, by the end of the war, tanks were established as a permanent and essential element of the British Army.