Migration history and network studies figure prominently in national and transnational historiographies, albeit with different implications. In national histories, the emphasis is often on emigration and immigration as well as on the construction of barriers between ‘insiders’ and ‘outsiders’, while the focus in transnational approaches is on networks of merchants, intellectuals, or travellers that sustained economic, cultural, or social links with less regard for administrative or geographical barriers. Bringing these points of view together has great potential but also faces significant hurdles: a major insight from one perspective may look like an interesting footnote in very small print from another.

Margrit Schulte Beerbühl, John R. Davis, and Stefan Manz are authors of important monographs on Germans in Britain, and experts on international migration, transnational merchant networks, and the treatment of minorities. In 2007 they edited a collection of essays on migration and transfer from Germany to Britain; this volume expands their perspective to encompass the British empire as a whole. The volume's aim is to use the German example to show that outside influences shaped Britain's imperial project significantly, and that British imperial history is therefore a transnational topic. The first chapter, by Mark Häberlein on colonial-era Pennsylvania, is one of the collection's highlights and sets out the possible dimensions of cooperation and influence. Häberlein identifies four types of actors involved in the mass migration of Germans to this part of North America: land speculators and immigration agents, head hunters seeking to attract personnel for industrial undertakings, go-betweens carrying information and goods from one side of the Atlantic to the other, and Protestant clergymen who served as intellectual mediators. As an expert on both Germany and North America, Häberlein is careful to calibrate the relevance of German actors by charting success as well as failure, and by comparing the German presence in the British empire to the impact that Germans had in French, Dutch, or Spanish ports focused on trade with America.

Margrit Schulte Beerbühl's approach is different. Building on her magisterial study of German merchants in Britain (published in German in 2007), she assesses the contribution of (mostly London-based) merchants of German origin to the transatlantic trade in textiles, slaves, and tobacco, as well as to Anglo-Indian trade. The conclusions vary widely. Whereas German linen cloth was a key British re-export to North America, the subchapters on other economic sectors describe a more marginal presence in the UK, which was in turn frequently only one building block of individual merchant families’ efforts to establish pan-European networks.

Ulrike Kirchberger's chapter again takes a broader view. In her dissertation (published in German in 1999), she presented the interesting argument that Britain attracted many Germans with imperialist ambitions between the failure of the 1848 revolution to establish a powerful German empire and German unification in 1871. This article presents a brief, updated version of her thesis by discussing transmigrants, settlement projects, merchants, experts, and missionaries from Germany.

While the overall focus is on economic networks and ties, two essays take intellectuals as their theme. John R. Davis's article assesses the impact of Max Müller, the noted expert on traditional Indian languages, on the governance of India. While Müller's influence on the appreciation of Indian culture in Britain was significant, his relevance to the administration in India (which, incidentally, he never visited) appears almost marginal: viceroys and senior civil servants thanked him politely for his books, but wrote either that they had found no time to read them at all or that they managed to read them only after they had left India. Angus Nicholl's study of the German-born Australian explorer Ludwig Leichhardt provides an equally nuanced portrait of the not entirely welcome contribution of an outsider to mapping an increasingly autonomous British colony.

Angelika Sauer's chapter on German-born immigration agents – the late-nineteenth-century reincarnation of Häberlein's go-betweens – shifts the focus to Canada, where the government appointed four would-be intermediaries to Germany (one of them female), all of whom failed to attract German immigrants in the numbers the government desired. Horst Rössler, by contrast, draws attention to successful cases of chain migration, using the emigration of sugar bakers and adventurers from northern Germany to Australia and New Zealand as an example. Finally, Stefan Manz's essay on attempts to set up branches of the German imperial navy league in the British empire makes clear why the volume is right to end in 1914: in ever more places, activists reported that German emigrants who wished to side openly with their fatherland faced increasing hostility as the imperial project open to outsiders gave way to a new vision that set greater store on loyalty.

While all the contributions to the volume are fascinating, their link to the conceptual approach is not always easy to see. Ulrike Kirchberger highlights one of the problems when she concludes that ‘Integration into the networks of British economic expansion diminished the power of ethnic attachment’ (p. 69): if the emphasis is on the impact that fluid transnational networks had on the British empire, how relevant a category is ‘Germany’? The centrality of impulses from Germany to British imperial history discussed in this volume also varies greatly. Where the focus is on Germans with imperial ambitions who remained in metropolitan Britain, their centrality is often open to serious doubt. This may be an unfair conclusion, however. Seen from Germany, the British empire was also far less important, say, for migration, than the United States, but this did not render it irrelevant. In the chapters that focus on the imperial periphery, it is evident that Germans were a significant presence – often the most numerous group of non-British European immigrants. As British imperial history is increasingly seeking to transcend the division between the dominions and the dependent empire, it might be interesting to think about a third volume that explores the German or European impact on British India, the Caribbean, or the African colonies. It would allow a more comprehensive assessment of transnational influences.