Much has been written in recent years of the resurgent imperial tendencies of the late Ottoman state. It should be remembered, however, that in the eyes of many it continued to be viewed as a vital force in the struggle against European colonialism. In particular, the Ottoman Middle East, and especially Istanbul, constituted one of the focal points of South Asian discontent and opposition to British imperial rule in the late 19th and early 20th centuries. Not only did it feature prominently in the South Asian Muslim imagination as the seat of the Caliphate, and as such a last bastion of Islamic sovereignty against European imperialist expansion, but it provided a space beyond the direct reach of British authority for dissidence and activism. In consequence, from the first rumblings of Indian anti-imperialist nationalism in the uprising of 1857 until Turkish Independence in 1923, there was steady traffic of anti-imperialists intellectuals, renegade ulema and mujahideen wishing to fight for the Ottoman cause that flowed to the Ottoman heartlands, both via Afghanistan and Persia to the north and intermingled in the burgeoning Hajj traffic. This paper focuses on the activities of this revolutionary diaspora specifically during the First World War and argues that they were important participants not only in the swelling Indian nationalist struggle, but in the Middle East theatre itself, though in complex and sometimes contradictory ways. South Asians collaborated extensively with the Ottoman and German authorities to disseminate propaganda and conduct a series of intrigues against the British in the Middle East, many centred on the thousands of Indian British troops deployed in the region, of whom a number defected. However, Indian spies were also widely deployed by the British themselves before and during the conflict. Rather than seeing South Asians active in the wartime Middle East as proxies for German, British or Ottoman interests, this paper emphasises them as active agents in their own right, attempting to navigate the complex webs of ideology, allegiance and intrigue in pursuit of their goals, at a time when later national identities had yet to fully coalesce. At the same time, their activities demonstrate the ways in which South Asia and the Middle East were bound together in this period, both by imperialist competition and the shared political and intellectual movements against imperialism that criss-crossed the continents opposing it.