It is fitting that my dissertation on the idea of intervention and protection of foreign subjects during the Anglo-Spanish War (1585–1604) has been published in the GHIL’s series, as it touches on one of the most researched periods of English history: the reign of Queen Elizabeth I and the Anglo-Spanish War. My study investigates the conflict-ridden relationship between Protestant England and Catholic Spain in the incipient Age of Confession as reflected in publications and drafts of declarations of war and war manifestos, which scholarship has shown to be sources of vital importance for the history of political thought in the early modern period.
Each side in the Anglo-Spanish conflict presented the war as intended to protect its adversary’s subjects. To analyse these justifications thus not only provides a new view of the dynamics of confessional and political conflict between England and Spain, but also uncovers early modern precursors of the idea of ‘humanitarian intervention’. Interest in this concept has been growing among historians in response to the heated political and legal debates on the development of international humanitarian law and humanitarian military intervention from around 2000–1. The concept of ‘responsibility to protect’ (R2P) was crucial to these debates. It caused controversial international discussion and as a result also drew the attention of historians to past ideas and practices of protecting foreign populations against their own rulers.
My attention turned to the war between England and Spain, which began in 1585 with Queen Elizabeth’s intervention in favour of the States General of the Netherlands opposed to Spanish rule, and ended in 1604 after several Spanish attempts to invade England and Ireland had failed. A peculiarity of the conflict was that both sides cited a need and duty to protect their foreign subjects to legitimize taking up arms. This perhaps unique constellation was possible because of the increasing impact of confessional thought on European politics, the internal religious tensions and conflicts of both monarchies, and more and more openly articulated international demands for confessional solidarity in the face of such conflicts.

While England’s intervention in 1585 aimed mainly to protect Dutch Protestants, who had been in revolt against the central Catholic power Spain and their sovereign King Philip II since around 1568, the Spanish party justified its war against England, pointing to significant support from Catholic refugees and exiles from England, as an intervention to liberate the Catholics still living there from the ‘heretical’ rule of a Protestant queen. The Spanish Armada against England in 1588, for instance, which became famous mainly because of its failure, was justified by the Catholic Englishman and religious exile Cardinal William Allen as a protective intervention in favour of English and Irish Catholics.
Although the need to protect foreign subjects against this background of confessional politics was seen as a legitimate public justification of war on both sides, the idea of protective intervention on behalf of foreign subjects remained problematic. It almost always prompted suspicion and accusations of support for rebellion and sedition, especially when it involved support for confessional opposition. Both the English Crown and the various apologists of Spain’s war against Elizabeth I reacted to this problem at two levels. First, as my analysis of the security arguments expressed internally in political memoranda and correspondence, council reports, and similar unpublished sources shows, England and Spain declared the protection of foreign subjects to be a necessity for their own monarchy’s security: defending a monarch’s own subjects from foreign threats had been considered a central aspect of bellum iustum (just war) from the time of St Augustine. Extending this argument to foreign subjects and intertwining it with the question of their security meant that a legally and morally controversial intervention in a foreign sphere was declared an act of (self-)defence to which there was no alternative. Second, both sides adopted the arguments and justifications of confessional and political opposition and resistance movements within their adversary’s territory to justify military intervention. England used the claims of Dutch propaganda against the Spanish, who in turn appropriated the accusations of the Catholic opposition to Elizabeth. By accusing their opponents of grave injustices and crimes, the intervention appeared to comply with the principles of a just war.
In the theory of contemporary international law, the idea that the tyranny of a ruler against his own subjects was a matter that also affected other rulers emerged in the wake of Europe’s colonial expansion and confessional division; rulers were called upon, in their role as upholders of God-given order and justice, to prevent or stop the mistreatment of subjects by their ‘natural’ lords. Many influential scholars of this period considered intervention justified where tyranny had created the conditions for legitimate resistance by the subjects. This thinking was articulated against the backdrop of traditional just war doctrines and found a counterpart in the political practice of public justification of war, including during the Anglo-Spanish War.
While my study thus makes visible how both sides used widespread political ideas on the obligations and limits of monarchical sovereignty and arguments for legitimate armed resistance to justify military invasions as protective interventions, it also uncovers recognizable differences.The argument relating to security, for example, reflected crucial differences between England’s and Spain’s approaches to European power politics: Elizabeth I emphasized that England’s security against Spain’s aggressions depended on supporting the Dutch in their defence against Spanish ‘absolute’ rule. The Spanish side argued that security was needed against England’s destructive activities in the broad interior of the Spanish empire, including England’s aid to the ‘rebels’ and pirates on the vital transatlantic sea routes. While the English justification for intervention emphasized the establishment of security through co-operation with the Dutch in order to achieve regional stability, the arguments on the Spanish side were about achieving security through hegemony.

And while both sides similarly used the protection of foreign subjects from tyranny and the defence of their traditional privileges and liberties as justifications for intervention, the Spanish side openly expressed the aim of achieving a confessional regime change in which the English and Irish Catholics were to participate. In addition, the Spanish side considered using an alleged Habsburg claim to the English throne to undermine the ‘usurper’ Elizabeth Tudor.
There were also confessional dimensions at stake. Elizabeth I did not use openly confessional arguments, but drew on legal and political ones. Her aim was probably to keep Catholic powers from closing ranks with Spain. For Spain, on the other hand, confession was a central lynchpin of its position. The Pope was invoked as a superior authority who permitted, or even ordered, interventions to do away with ‘heretical’ rule. Parallels were construed between the war against England, interventions on behalf of Catholics, and crusades against heretics. This decidedly religious angle remained a peculiarity of the Spanish and their partisans among English exiles.
Differences also become apparent in the audiences to which the English and Spanish justifications for intervention were directed. Elizabeth I addressed hers to a European audience that included Protestant sympathizers of the Dutch as well as Catholics, whose neutrality had to be safeguarded. Spanish justifications were aimed exclusively at a Catholic audience, which was sworn to solidarity with their threatened fellow Catholics as part of the larger struggle against Protestantism.
My new book thus tells the story of two different versions of the idea of intervention on behalf of foreign subjects which testify to different conceptions of confessional and political order in Europe, and to differences in political thought and political languages in England and Spain. The idea of protecting foreign subjects was not a mere pretext for going to war; the sources demonstrate that some sense of monarchical ‘responsibility to protect’ did indeed exist or emerge. It was, however, never separated from England’s and Spain’s political self-interest; rather, it was aligned with it.
The featured image shows the Battle of Heiligerlee (1568) as depicted by Frans Hogenberg. Artwork in the public domain, provided by Wikimedia Commons.
OpenEdition suggests that you cite this post as follows:
Julian Katz (July 13, 2021). Intervention on Behalf of Foreign Subjects during the Anglo-Spanish War, 1585–1604. German Historical Institute London Blog. Retrieved March 24, 2025 from https://doi.org/10.58079/p1q8