This article examines the response of the leading British socialist H. M. Hyndman to the British empire. It suggests that historians have provided an oversimplified and inaccurate account of that response, despite the significance and influence of his critique. This article examines Hyndman's analyses of empire in greater detail, considering many more public and private sources. It charts the chronological development of his response, examining the context, comparing his views with those of other British and continental socialists, Marx, and the ideas of ‘new imperialism’ generally. The article ultimately argues that though Hyndman's response evolved, with changes of direction missed by historians, he would remain a constant critic of his imperial world.