By Alex Richards
The latter stage of the Thirty Years War- usually referred to as either the French or Franco-Swedish phase- became increasingly geographically disparate as a result of the different forces now incorporated. As well as the Hessian conflict already covered in these articles, three distinct areas of warfare can be characterised- the northern front led by Sweden and spanning from Lower Saxony across to Silesia; the western front led by France and Bernhard of Saxe-Weimar in the Rhineland and Swabia, and the Franco-Dutch war in the Spanish Netherlands which formed part of both the Eighty Years War and the 1635-59 Franco-Spanish War as well as being linked into the Thirty Years War itself. As such, the forthcoming articles for this period will likewise follow geography rather than strict chronology, beginning with a return to the Swedish front.
The Franco-Swedish Alliance
By 1635 Sweden had been on the retreat near continuously since the disastrous defeat at Nördlingen and the subsequent collapse of the League of Heilbronn. The Peace of Prague took this one step further, with the Electorates of Brandenburg and Saxony defecting to the Imperial side and entering into open conflict with Sweden. Sweden herself had been excluded from the peace talks, and despite the failure of Saxon efforts to bring about a mutiny of her German mercenaries the situation remained poor for Sweden.
Having withdrawn to the more defensible core of their conquests- Mecklenburg, Pomerania and parts of Brandenburg, Oxenstierna turned to diplomatic means to shore up Sweden’s position, undertaking negotiations with the French for renewed financial support. Richelieu was receptive- not least because it would keep pressure on the Emperor and prevent additional support being sent to Spain. As a result, France and Sweden signed the Treaty of Wismar on 20th March 1636, whereby France paid the 60,000 thalers owed in arrears since the death of Gustavus Adolphus and promised more on condition that Sweden agreed not to make a separate peace with the Emperor. Oxenstierna initially refused to ratify the latter position- finding it overly restrictive when all he needed was the announcement of the alliance for his own purposes- but the initial failures of the French advance against Spain meant that Richelieu had little choice but to accept this for the time being.
However, while Sweden used these funds to hire 4 additional British regiments, Ferdinand of Hungary- the future Emperor Ferdinand III who was essentially running the war effort at this point- was not inclined to give the Swedes respite. As such, Ferdinand utilised the lull in fighting elsewhere to transfer 10,000 troops under Melchior von Hatzfeldt to the Saxon front, where he soon succeeded in becoming the formal commander of the 8,000-odd Saxon troops as well. Opposing him were the 12,000 men of Johan Banér’s army at Brandenburg, with a further 6,000 in Westphalia under the Scottish Alexander Leslie.
The Battle of Wittstock
Distrustful of his men after the recent mutiny threat, Banér retreated, and Hatzfeldt swiftly laid siege to Magdeburg, capturing it on July 13th, then advancing into Brandenburg where he left 4,000 men to secure the loyalty of the electorate. These he replaced with the troops of Rodolfo Giovanni Marazzino from the Oder, and advanced towards Pomerania. Banér meanwhile had linked up with Leslie during the latter’s retreat across Lower Saxony, and summoned a further 3,800 troops from the Pomeranian garrisons. On October 4th, the two sides met at Wittstock just south of the Pomeranian lakes with roughly equal numbers of men, though the Imperial forces were able to dig in and establish a stronger defensive position first.
Banér found himself forced to approach across a stream and marshy ground in a direction tangential to the Imperial lines, and as a result undertook a very risky strategy, splitting his army into three different groups. While 5,800 men under Leslie were directed to pin down the Imperial centre, Banér sent 3,100 cavalry under James King by a lengthy route to attack the opposing flank, while he led the remainder to try and flank the Imperial army. While Banér initially faced heavy resistance, Leslie was able to give him sufficient support to prevent a collapse until King successfully attacked the Imperial reserve, capturing the artillery in the process. Both sides had taken severe losses- perhaps 3,500 for the Swedes and 5,000 dead or captured for the Imperial army- but it was Hatzfeldt who took the decision to retreat, maintaining the army but abandoning their baggage trains in the process.
As should be apparent from the casualty figures, Wittstock was a close run thing. By splitting his army Banér opened his army up to being defeated in piecemeal manner, and his own attack on the Imperial forces was almost forced to retreat back towards the river. Had his army been repulsed, it would have been quite possible for Hatzfeldt to press the advantage and force the Swedes to be the ones to retreat.
Strategically this would have been disastrous for Sweden. With her last significant force in the Empire defeated, and likely shedding the German mercenaries and troops through a combination of low morale and the fear of reprisals, Hatzfeldt would have been in an ideal situation to roll up the Swedish positions in Mecklenburg and Pomerania, likely forcing them to abandon all but a handful of outposts like Stralsund. At that point, regardless of any promises to France, Oxenstierna would almost certainly have been forced to accept a peace treaty which left Sweden without any sort of territorial gain to show for all her efforts.
The Failure of Mediation
As it was, Banér was able to advance, occupying Brandenburg, relieving Erfurt and capturing Torgau in Saxony the following February. Paradoxically this served to strengthen Ferdinand’s hand as Georg Wilhelm moved firmly into the Habsburg camp, now reasoning that there was no hope of Oxenstierna offering territorial gains for Brandenburg and increasingly concerned that Pomerania would be ceded to Sweden in its entirety to buy peace. This last matter, while unlikely considering Ferdinand still hoped to enforce his desired peace on Sweden, gained renewed importance after the death of the Pomeranian Duke Bogislav XII, last scion of the ancient House of Greifen (or Griffin) on 10th March 1637, whereupon the Swedes promptly turned their occupation into a formal annexation as per the terms of the treaties they’d forced him to sign in 1631.
Wider peace efforts were still continuing at this time, with the confluence of the Peace of Prague and Franco-Spanish War being taken as the signal by figures as varied as the Pope, the Protestant electors and Charles I of England to try and arrange a peace treaty, but for the moment France and Sweden remained separate considerations.
On the French front, Pope Urban VIII moved from his prior position- which largely consisted of expressing concern at the fighting while attempting to avoid appearing too close to the Habsburgs- to offer to sponsor a peace conference in Cologne. While the offer which Richelieu presented- to renounce Alsace and negotiate over Lorraine so long as the French protectorate over the Trois-Évêchés was recognised- was substantially more generous than what was eventually conceded at Westphalia, Ferdinand’s reluctance to even consider peace- his envoys only arrived 6 months after the Papal legate did- meant the affair was a desultory failure. Indeed it may well have been fatally wounded from the start as Urban’s refusal to include the Protestant princes from negotiations effectively handed France an open goal diplomatically- their insistence that the negotiations needed to include not just the Emperor but his subject princes, rather than accepting Venetian offers to be a go-between, would become a cornerstone of French negotiations to come.
To the north, the Protestant Electors sought ways to convince Sweden to leave the Empire, but could come up with no better solution than to buy them off- offering a retention of tolls and a port in Mecklenburg- a potentially ruinous financial situation which was only exasperated by Ferdinand’s expressly stated views that payment should be restricted to the Protestant princes for having ‘invited in’ the Swedes in the first place. Defeat at Wittstock might have convinced Oxenstierna to accept this, but with the victory there he remained committed to seeking the retention of Pomerania. Meanwhile a conference in Hamburg backed by the Danes had been rumbling on since 1633 without any real success beyond offering a place for the various Protestant princes to discuss matters.
Probably the only greater failure was the efforts of the delegation Charles I sent under the Earl of Arundel to try and secure a restoration of the Palatinate, which despite great expense and the fact that Frederick V’s son Karl Ludwig had now come of age could present no compelling reason for either Bavaria or the Emperor to consider reopening the matter. Emperor Ferdinand did manage one great success however- managing to secure the election of his son Ferdinand of Hungary as King of the Romans a mere month before his death.
It would, however, take more defeats at Swedish hands to convince the new Emperor that it was time to negotiate.
Alex Richards is the author of Tippecanoe and Wallace Too, published by SLP