This chapter focuses on Callwell’s role in the inception, conduct and aftermath of the Dardanelles Campaign (1915). Callwell occupied the important position of Director of Military Operations (DMO) at the War Office (1914-15) and therefore played a central role in shaping policy and strategy. He was also a key witness at the Dardanelles Commission (1916-17), an enquiry set up to investigate the causes of the Allied defeat. Finally, Callwell wrote extensively on the campaign, including his book The Dardanelles, published in 1919 as part of his Campaigns and Their Lessons series.

This chapter examines Callwell’s contribution to the ‘naval school’ that emerged as a result of increased interest in matters of imperial defence in the late nineteenth and early twentieth centuries. It argues that Callwell’s work was distinctive, based on his position as a ‘khaki-clad maritime theorist’, a soldier looking at amphibious warfare from the landsman’s perspective. It also explores Callwell’s time at the War Office, 1903-7, during which he was a practitioner as well as a theorist of strategy. Finally, it assesses Callwell’s literary output during his retirement, especially his writing on the Territorial Army.