This dissertation asks why, after years of close cooperation between groups, England and the Netherlands went to war against each other in 1652. In the 1630s and 1640s, Dutch and English people collaborated on imperial projects all around the world. At the same time, Dutch merchants loaned enormous amounts of money, equivalent today to hundreds of millions of dollars, to English borrowers. English and Dutch groups worked toward offensive and defensive alliances and participated in each other’s political struggles, while Englishmen and Dutchmen served in and funded each other’s wars. The connections between groups were sometimes surprising: Dutch Calvinists often allied with English Arminians, while Dutch Arminians allied with English Calvinists. Looking at personal papers, notarial documents, treasury books, newspapers, pamphlets, sermons, and company records, I have found that political and ideological factors combined in a way that led these groups to emphasize the religious values they shared over those on which they differed. While support from the States of Holland group in the Netherlands was crucial to the parliamentary war efforts in England, support from the Dutch Orangists to the royalist cause was greater in volume and only increased over time. I argue that financial connections between Dutch and English groups contributed to widespread Dutch support of and investment in the Stuart government. It was in part to diminish this support that the English government wanted war with the Netherlands in 1652, and it was largely to protect their investment that Dutch merchants wanted war with England. Dutch investment in the English royal family contributed in a significant way to the outbreak of the First Anglo-Dutch War.

Western European countries are currently grappling with the legacy of their imperial pasts. In the Dutch and English cases, these are tightly intertwined. This dissertation untangles the religious, ideological, and financial connections that brought Dutch and English people together across the world. It shows that they collaborated on imperial ventures because they sought profit and the Protestant cause, not national glory. Recent scholarship has debated the nature of empire at the beginning of the period of European expansion, particularly in England. Many point to the distance early English ventures kept from the crown, and their leadership by small groups of men, to differentiate them from projects like the British Raj in India in the nineteenth and twentieth centuries. Considering the planned and actualized Anglo-Dutch imperial ventures of the seventeenth century adds a new element to this discussion. Some ventures worked closely with the governments of England and the Netherlands, while others were more independent, but all of them included an element of collaboration across states. None of their leaders pursued their projects for the sake of the Netherlands alone or for the sake of England alone, demonstrating that early forms of imperialism were different from what people often picture when they think of "imperialism" or "colonialism" today.