PoDs of the Thirty Years War - Part XI

Updated: Aug 18

By Alex Richards

The Siege of Breda in 1624, by Peter Snayers

If, for the Stuart Realms, the question is why they weren’t more involved in the Thirty Years War than they actually were, for the Dutch, the biggest question is whether their relative lack of involvement in the conflict is more of a triumph of historiography over history.


Certainly to contemporary observers, the renewal of hostilities between the Dutch Republic and Spain was viewed as simply another part of the wider conflict within the Holy Roman Empire- an Empire of which the Dutch were still officially a part. Frederick V’s exilic court lay in The Hague, Spanish desires to secure their supply lines were of paramount importance to their actions in the Palatinate and the Valtellina, and Protestant mercenary forces regularly moved between direct action for the Dutch and action in the wider Empire. Indeed the Peace of Westphalia included the Treaty of Munster finally ending the 80 year Dutch War of Independence, both from Spain and the Empire itself.

Whether it’s the fact that the Dutch conflict was, for the most part, unconcerned with the Palatinate, the Emperor or the Religious Peace of Augsburg, or the fact that the preceding years of the Dutch struggle for independence allow for an artificial barrier to be drawn up between the two however, the fact remains that while acknowledged these days as part of, and influenced by, the wider conflict, the latter stages of the Eighty Years War are usually seen as something distinctly different from the Thirty Years War. In an attempt to ensure this article remains (relatively) concise, therefore, we’ll only be focusing on whether the Dutch could have been brought into a much more interventionist role in the Empire than historically.

The Twelve Years Truce

Pont Farnese blown up during the Siege of Antwerp, 1585, nearly taking Alexendre de Parme with it.

Dutch involvement in the Thirty Years War needs to be considered against the background of events during the Twelve Years Truce between them and Spain. Starting in 1609, following 40 years of near-continuous warfare and, in particular, the lack of a decisive blow one way or the other since the Fall of Antwerp in 1585, the truce marked the point at which the Spanish conceded that at least part of the former Habsburg Netherlands would be an independent nation and moved instead to ensuring that this would be as small a part as possible.

This is not to say that the Dutch remained at peace for this period, however. In 1609, war broke out over the disputed succession of the extremely wealthy and regionally powerful United Duchies of Jülich-Cleves-Berg between the Lutheran Elector of Brandenburg and the Catholic Duke of Pfalz-Neuburg (with Emperor Rudolph II also initially attempting to enforce a claim of his own). Over the course of the war, the Dutch intervened on the Protestant side, and the Spanish on the Catholic side, though both carefully ensured that no direct clashes occurred. There was, in any case, little active fighting in the 5 years before the duchies were divided by the Peace of Xanten, and Dutch involvement was primarily to serve as garrison troops, though they did take an active role in besieging some locations. The Dutch would also prove to be very pragmatic allies- garrisoning cities as far south of Jülich at times, but also being willing to surrender positions and withdraw rather than risk large troop losses unnecessarily.

Intervening in the War

The Siege of Aachen during the Julich Succession

The War of the Jülich Succession thus establishes the blueprint for any likely direct involvement by the Netherlands in the wider Thirty Years War. With the army of Flanders as their chief focus, any military excursions would be restricted to Westphalia or Lower Saxony, and would likely consist largely of garrisoning cities and fortresses on the potential approach routes to the Netherlands up the Rhine or Weser, or lending of engineers to strengthen fortresses. It is therefore unlikely, save for a situation where the Spanish have been utterly defeated in the Southern Netherlands, that the Dutch could be encouraged to actively involve themselves further afield. Even the Palatinate, despite the potential benefits of being able to harass Spanish supply lines to Flanders, is at sufficient distance, and was sufficiently isolated from the Netherlands itself, that such an excursion would almost certainly seen as creating too vulnerable a position to sustain for even the short term - particularly considering that the forward positions garrisoning towns in Jülich and Mark on the behalf of Brandenburg were comprehensively dismantled in 1621/22 when the Spanish finally made an effort at it.

Fundamentally, the issue for the Dutch was that, absent an explicitly hostile army in Westphalia, any expenditure of resources in the wider Empire could almost certainly be better spent pushing forward into the Southern Netherlands, which after all was both closer and offered much greater strategic and economic benefits for the Dutch themselves. It’s likely that if Ferdinand II had been successful in enforcing the Edict of Restitution, then the Dutch would have been part of any coalition of Protestant powers assembled to overturn this by the Danish or Swedes. Beyond this, the historic trend of absorbing the remnants of various defeated mercenary armies that persisted through the Palatinate and Danish phases of the war would be the most likely direct interaction in Germany.

Indirect Interactions

While the prospects for direct interaction beyond the Netherlands are low, their local war with Spain offers much in the way of secondary effects on the course of the Thirty Years War. As a general rule, the worse the Spanish were doing in the Netherlands, the more they felt the need to secure supply lines to Flanders, Austria, Bavaria or other key allies in the wider conflict through strategic targeting of Protestant communities.

The Surrender of Breda, 1637

Historically this would lead to such consequences as the occupation of the Palatinate and the devastation of the Valtellina, but depending on circumstances could see the target of Spain’s attentions move anywhere across Swabia, or move into direct conflict with France over the fate of Alsace depending on the stage of the war. In turn this tended to lead to verbal clashes between Spain and the Emperor (albeit with the latter acutely aware of how much he depended on the former), or a greater sense of threat among the Protestant powers of the Empire putting them into a more combative mood.


While an examination of the Eighty Years War is beyond the scope of these articles, the loss of Breda for a second time in 1637 was considered the start of the slow Spanish retreat that would lead to peace 11 years later, and it’s quite possible that preventing its fall in the first place would have seen the war end at an earlier date. Had the Dutch been more successful still in the 1620s, securing more victories and pushing the border south towards (though probably not including) Antwerp, it might even end up being the case that the 1635 Peace of Prague is sustained in the longer term.

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Alex Richards is the author of Tippecanoe and Wallace Too, published by SLP

© 2019, Sea Lion Press.

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