Jorun Poettering’s Migrating Merchants is a well-researched and extensive study comparison of the challenges and opportunities that Portuguese, Netherlanders and Hamburger merchants confronted in the trade between Hamburg and the Iberian Peninsula. Poettering, taking into account all previous relevant works, draws on archival sources, published and unpublished materials, and advances our understanding of the subject to important new insights.

The book starts with the historical context that framed the commercial trade between Hamburg and Portugal. The second part deals with merchants, their trade and routes, and the infrastructure and services used to solve problems of long-distance commerce, as well as the merchant’s status as foreigners. The last part explores how confidence, reputation, and religion influence the connections, relationships, and flexibility of the social networks of these merchant groups.

When contemplating Portuguese Jews, Poettering goes further than others, such as Werner Sombart, Herman Kellenbenz or Jonathan Israel, and considers that their success was based in multi-religious and multi-ethnic inter-group confidence, solidarity, and cooperation to achieve mutual benefits. Thus, her view is more in line with the work of Francesca Trivellato (e.g., The Promise and Peril of Credit, Princeton University Press, 2019, and The Familiarity of Strangers, Yale University Press, 2009).

The Portuguese, for instance, suffered discrimination as New-Christians in Portugal and as Jews in Hamburg. Consequently, Portuguese merchants were less integrated and assimilated in Lutheran Hamburg, where they preserved their language, customs, religion, interests, and identity. Moreover, there, they made use of private enforcement mechanisms for commercial contracts, yet always supervised by state and city laws and tribunals. Still, they received no support from Portuguese authorities and had no chance to return there, because that could expose family members and partners to the Inquisition. They were also riskier partners to have relative to Old-Christians or foreigners because they could be arrested, and their possessions could be seized. Consequently, Poettering concludes that these Jewish and New-Christian networks were less competitive. This, however, contradicts the idea, also defended in the book, that their commercial networks were composed by people from different faiths and nationalities, even if operated by a single ethnic group.

The vulnerability of the Portuguese, therefore, required disciplined solidarity among their members and the obligation to engage in the community. It also resulted in absolute leadership and excessive power of the Board over the members in order to preserve their collective reputation. There was the perception that their livelihoods and survival was at stake if they did business outside the community, so the confidence and reputation of trusted colleagues as well as family bonds was of great importance.

Hamburgers and Netherlanders could have been as numerous as the Portuguese, but they were probably lesser known because they were more assimilated and, in that process, they lost their group identity. They did not settle in Portugal to escape prosecution; they faced no pressure to organize because they rarely had to assert their rights; they were respected socially; they learned Portuguese (children were sent to Hamburg to learn German); and, they assumed the religious identification of the majority of the population. Furthermore, they joined brotherhoods, not as a matter of self-defence, but because the conversion to Catholicism opened the way to the most influential business circles.

The Netherlanders had a lesser sense of solidarity and were more heterogeneous. They belonged to the reformed churches and were led by an elite that defined the behaviour and sanctions in the community. As with the Portuguese, the highest form of punishment among the Netherlanders was excommunication. However, the reformed Netherlanders had more opportunities in Portugal and were less obstructed by the Inquisition.

Poettering underlines that local conditions could also have affected the capacity of these merchants to succeed. For instance, while in Portugal the Crown aspired to have a global commercial monopoly, it had the Inquisition enforcing rules, at times against their best interests. In contrast, Hamburg was a city-state ruled by an oligarchy of elite merchants with little clerical power.

Moreover, these different states provided different opportunities for foreign merchants. In Portugal, the authorities welcomed foreign merchants, mainly since the beginning of the overseas expansion, because they provided many of the domestic consumption necessities, financed wars, conquests, and the trading ventures of the Portuguese Kings. Because of that, they were granted a legal status oftentimes more favourable than that conferred to their local colleagues and competitors. For instance, Hamburg merchants in Portugal received support from the Hansa, in the beginning, and from the city-state afterwards. They also had a consul to turn to and they were protected by Hamburger institutions and their own ruling authorities.

In contrast, foreign merchants in Hamburg were treated more ambiguously. Hamburgers favoured local over foreign merchants and provided advantages to the latter only selectively. The Netherlander could become citizens, achieve high offices, and be integrated into Hamburg’s economic organization, while Portuguese merchants could not be citizens because they were Jews and were not recognized as equals. The nature of the contracts they used was also quite different: Netherlander relied on individual contracts whereas the Portuguese signed collective contracts.

Although Poettering states that there was no segregation in business, there are allusions to the idea that conditions were not the same for everyone. Trade in most crucial commodities such as grain, wine, and salt was limited to Hamburg citizens. Because of this, foreigners focused in less essential goods like wax, dyes, cloth, and sugar. And, of course, their incomes reflected that difference. Still, almost half of the long-distance trade in Hamburg was handled by Netherlanders, who together with Portuguese merchants controlled 50 percent of trade between Hamburg and the Iberian Peninsula.

Poettering concludes that the Atlantic trade was based on flexible networks and that ethnic and religious backgrounds mattered little. All groups had to sustain networks, and to struggle with political, religious, and legal barriers. All had the capacity to deal with different experiences and adapt their actions and behaviour accordingly. So, their personal experience and commercial capacities resulted in flexibility and innovation, forcing the host cities to change to guarantee facilities such as introducing multilingual brokers and notaries and allowing the legal system to be flexible as well.

Overall, the book undertakes a daunting task, which is comparing the differences and commonalities among three merchant groups in two locations, examining their networks, and the solidarity inside them. These comparisons are not easy because they include different cultural groups, types of government, religious attitudes, and administrative structures. Even the documentation is not comparable, namely Inquisition files in Portugal, statistical data in Hamburg, and the books of the Portuguese community (far richer than the documentation of German and Netherlander merchants). At points, the comparison is too complex because all the conditions, spaces, institutions, and organizations were completely different for these groups.

In the end, the book is a comparison of ethnic and religious groups in commerce, but the conclusion is that those issues did not matter for trade, innovation, flexibility, and incomes because all groups, being different, had the same purpose and used the same instruments for cooperating and competing with each other in an interconnected world.