By Alex Richards
In the last article I discussed the potential outcome of a Danish victory in their intervention into northern Germany after 1625. Yet for all that this eventually ended in a reversion to the pre-war status quo for Denmark, the extreme imbalance between their performance and that of the Imperial forces under Wallenstein and Count Tilly suggests that such a prospect was remote. It is to their opponents- Ferdinand II and the Catholic League- that I'll be examining in this article.
The Naval Problem
The chief issue for an Imperial victory is that which led to the historical stalemate in the first place- while vastly superior to the Danish army, the Imperial forces had no available fleet with which to attack the Danish islands from. Neither Hamburg nor Lubeck, the great Hanseatic trading cities of the area, would sell or rent them ships for this-presumably fearing a vengeful Denmark should the attack fail- and there were few other states with sufficient port facilities to serve as embarkation points.
Of these, the two Mecklenburgs- Schwerin and Güstrow- ruled by brothers John Albert and Adolf Frederick- had secretly allied with Denmark and were treated as enemies of the Imperial Crown by count Tilly after the battle of Lutter in 1626. They were swiftly occupied by Wallenstein, together with the ports of Wismar and Rostock, both of which had been founding members of the Hanseatic League with Lubeck but had declined in the 16th Century and were now firmly under the control of Mecklenburg-Schwerin. Neither port was particularly large and the Danes were soon able to establish an efficient blockade of the Mecklenburg coastline, including descents to destroy the naval facilities at Wismar in 1628. Attempts to use Danish ports in Jutland were similarly hindered by the withdrawal of the Danish navy before they fell, and a similar attack on Alborg that rendered it unable to serve as an embarkation point.
The rest of the Baltic coast to the border with Poland was at this time controlled by the Duchy of Pomerania. Pomerania, along with Brandenburg and the minor states of the Upper Saxon Circle, had attempted to maintain neutrality in the conflict since it began, but now came under increasing pressure to allow Imperial troops into the country to deny the Danes a potential entry point.
The year 1627 was the watershed- Swedish troops landed in Pomerania and crossed the border as part of their war with Poland-Lithuania, who were allied to Ferdinand II, recruiting from Pomerania as they did. Partially in response, though mostly for strategic goals, Wallenstein ordered the occupation of Pomerania and the seizure of her ports and vessels. While Duke Bogislaw XIV attempted to pay off the Imperial troops, Wallenstein was not to be dissuaded and forced a capitulation which allowed Imperial troops to occupy every town in the Duchy save for those which were his immediate properties. Only Stralsund- another former Hanseatic port and traditionally chafing of Ducal authority- refused and was placed under siege from 1628, resisting with Danish, and later Swedish, support.
There was yet another issue for Wallenstein's naval hopes- the simple absence of big ships even after securing as much as he could from Mecklenburg and Pomerania. Despite punishing ship taxes on Mecklenburg and a ruinous occupation of Pomerania, the Danish destruction of the naval facilities at Greifswald and the lack of funds meant that attempts at building a naval force from scratch failed, and it wasn't until the Polish navy fled to Wismar in 1629 that Wallenstein could claim to have a naval force of any real strength. Even then, lack of funds meant that the sailors on those ships went unpaid, and the rotting hulks remained at harbour until the Swedish army captured the town 1632.
To Stralsund and victory?
The siege of Stralsund, which started in May 1628, represents the best opportunity-perhaps indeed the only one- for a more successful Imperial campaign. Initially defended by 2,500 citizens, this was swiftly reinforced first by 900 Scots in Danish service, and then from June 20th by 600 Swedish forces- also mostly Scottish. Within the week Stralsund had concluded a formal alliance with Gustavus Adolphus of Sweden, bringing them into the war. Attempted Imperial assaults to take the town on May 26th/27th and June 27th failed- the latter after inflicting heavy casualties- and an attempt by Duke Bogislaw to create a negotiated surrender on June 29th was foiled by the arrival of fresh Swedish reinforcements.
The tide effectively turned at this point- Alexander Leslie, another Scot in Swedish service, led further reinforcements of 1,100 soldiers, Denmark gave another 400 on July 2nd, and by the end of the July Wallenstein was forced to acknowledge defeat and withdraw.
Had any of the early assaults been successful- especially those before the formal involvement of Sweden in the conflict- it's possibly Stralsund would have been able to serve as a key naval base for Wallenstein, with the protection of the island of Rügen potentially preventing a Danish attack. On the other hand, a Danish descent destroying the naval facilities remains a strong possibility and the difficulties of building or acquiring sufficient ships for operations are going to remain in force.
Much as with a Danish victory on land, therefore, an Imperial victory on the seas relies on having a long run of good fortune and allohistorical successes to ensure that a navy is in place to transport troops to the islands. Assuming sufficient troops could be moved over, however, there's a strong possibility that Wallenstein would have been able to force another defeat against Christian IV of Denmark, one sufficient to require him to agree to territorial losses in return for peace.
There are few indications as to what concessions Ferdinand II would have demanded in such a situation, but loss of his control over Hamburg, Lubeck and the Bishopric of Strelitz is a certainty, and an attempt to remove him from Imperial politics altogether seems likely. to achieve that, it would be required to force the cessation of Holstein- Denmark's only territory within the boundaries of the Empire. While this could spark an early version of the Schleswig-Holstein question as the two duchies had been eternally united by the 1460 treaty of Ribe. However Ferdinand, given his views elsewhere, is likely to simply regard Holstein as a fief that can be separately revoked and given to a supporter. Wallenstein was historically given both Mecklenburgs and the Bishopric of Schwerin as a personal fief in 1628, and would be the logical person to be granted Holstein, likely in exchange for Mecklenburg, but a reward for Count Tilly is also a potential.
A lasting Peace
While somewhat unsatisfactory, the Danish phase of the war serves as an illustration of when the actual historical course of events is the most likely to occur without a prior change in situation. Any clash that involves Wallenstein and Tilly on land against Christian IV of Denmark is going to favour the former heavily. Any attempt at a naval invasion of the Danish islands is going to be a strong difficulty for the Imperial forces to even organise, let alone carry out. But either an early fall of Stralsund- before the chance for a Swedish intervention occurs- or potentially both sides continuing to respect Pomeranian neutrality forcing a negotiated settlement on the historical grounds could lead to an opportunity for the Thirty Years War to end here, with Ferdinand II triumphant in the Empire. Assuming the Swedish and French don't just intervene anyway of course. Ferdinand's vision for the Empire is something we have rather more evidence for, and so it will be this that the next article will be examining in detail
Alex Richards is the author of Tippecanoe and Wallace Too, published by SLP