Under its terms the Peace of Prague was open to almost any German ruler who cared to accede to it. It promised amnesty to rulers in arms against the Emperor, save only for those very few who had rebelled before the landing of the Swedes.
By August, 1635 most of the Imperial Free Cities and lesser rulers, Protestant and Catholic alike, had acceded to the Peace. But it was the greater princes whose attitude would determine the ultimate fate of the Peace.
Maximillian of Bavaria, as Duke of Bavaria and as head of the Catholic League, had uniformly maintained a policy separate from the Emperor’s. He had always been Ferdinand’s ally, but had always extracted a price for his aid.
Under the terms of the Peace, however, he was required to submerge his forces within the Imperial army. The Emperor gave his own daughter, Archduchess Maria Anna, to Maximilian as a child-bride. He granted the Bishopric of Hildesheim to Maximilian’s brother the Elector of Cologne. He granted to the shredded remnants of Maximilian’s army the same degree of limited independence granted the Saxon forces.
In the end, Maximilian gave up his freedom and acceded to the Peace.
Georg-Wilhelm, Elector of Brandenburg, also joined the Peace. However, the price he extracted was a concession by the Emperor that no peace with Sweden would be made which did not protect Brandenburg’s expectation in Pomerania. As Sweden would never, short of absolute defeat, give up her bulwark on the southern Baltic shore, this guaranteed that the war would continue.
The 1629 Treaty of Altmark was soon to expire. If war between Poland and Sweden broke out anew the Swedes would be compelled to withdraw from the Empire entirely. The French, cognizant of the risk, dispatched the Count d’Avaux as their representative to the talks at Stuhmsdorf. The English and Dutch also sent representatives. In September, 1635 the truce was renewed for twenty-six years, although on terms were less favorable to Sweden than those of the Treaty of Altmark.
The Swedish army under Tortensson which had been garrisonning Poland marched at once to Germany. The need for them there was great.
Banér’s Swedish troops had retreated from Bohemia and taken up quarters in the Bishopric of Madgeburg. The army was unpaid, mutinous and plagued by desertion.
On 16 October, 1635 the Saxons formally declared war on the Swedes. It appeared that Gustavus’s nightmare, that the Saxons would cut the Swedes off from the Baltic and all succour, was about to be realized.
The Saxons and their new Imperial comrades moved down the Elbe to cut off the disorganized Swedes. Another force in the north sought to prevent Tortensson’s army from providing support.
Howeve, Banér was able to break through the Imperials at Dömtiz. When he crossed the Elbe into Mecklenburg, he was met by Tortensson. The Swedes were safe in their bastion: Mecklenburg and Pomerania.
Probing attacks by the Saxons at were summarily beaten back, on 7 December, 1635 at Goldberg and on 17 December, 1635 at Kyritz. The Swedes even managed to recover Werben and Havelberg.
Meanwhile on the Rhine, the triumphant advance of Imperial arms continued. The French, on whom all resistance to the House of Austria now depended, had opened the war by massive offensives on the Low Countries, Spain and Italy. They failed on all fronts.
Bernhard of Saxe-Weimar, exposed at his forward position in Spiers, could not attack without French support. The French Rhine army under had been held back near Lorainne to protect against Duke Charles’s attempt to regain his patrimony.
While Bernhard retreated, the Imperials took Kaiserslautern and Heidelberg and besieged Mainz. Finally, on 27 July, 1635, Bernard was joined by the French under Cardinal La Valette. On 8 August, 1635, the siege of Mainz was raised. His army sadly diminished, Bernhard was compelled to fall back to Metz in French-occupied Lorraine. By December, Mainz was in Imperial hands.
The failure of French arms had shaken Richelieu. He realized that the safety of the Rhine, and thus of northern France, depended on the experienced troops of Saxe-Weimar.
For his part, Bernhard realized that no further help was to be expected from Swedes, distant and poor, or the Protestant princes, all of whom had joined the Peace of Prague. Unwilling to lay down his arms and seek Imperial pardon, Bernhard began to negotiate with the French.
On 19 November, 1635, Bernhard and the French agreed that, in return for annual subsidies of 1,000,000 livres Bernhard was to maintain an army of 12,000 foot and 6,000 cavalry. Bernhard himself was promised the Landgravate of Alsace, and rights over all lands conquered by him.
The Swedes were irate that their French allies had “debauched” an army sworn to the Swedish service. But there was nothing they could do about it.
If 1635 had been a bad year for French arms, 1636 was to be worse. It was not the campaigns in Germany: these were successful. Bernhard and La Valette relieved besieged Hagenau and took Zabern, making themselves the masters of almost all of Upper Alsace.
In France proper, things were different. On advice of Maximilian of Bavaria, the Cardinal-Infante determined on a fast-moving invasion of France through Picardy and the Franche-Comté.
The Cardinal-Infante, having borrowed Johan von Werth’s cavalry from the Emperor, erupted into Picardy. He advanced as far as Corbie. Meanwhile, Charles of Lorraine and Gallas were advancing from the Franche-Comté. Paris was filled with panic and the fall of Richelieu was expected daily.
In the end Louis XIII rallied enough troops to drive the lightly-armed invaders from Picardy. Gallas found himself stopped by the stubborn garrison of Ste.-Jean-de-Losne. The invasion melted away as if it had never been.
One isolated garrison held out for Sweden in southwest Germany. The city of Hanau, under command of Sir James Ramsay, had been besieged by the Imperials since the fall of 1635.
That city was the homeplace of Amalia Elizabeth, wife of William of Hesse-Cassel. At her urging, he united with the French and the Swedish armies to attempt the relief of the place. On 16 June, 1635, the relief succeeded.
However, the anti-Imperial forces were too weak to hold the place. Bernhard, who was closest, was penned behind the Rhine and the Swedes and Hessians could not maintain an army so far from their bases. The siege was renewed and the city surrendered on terms.
For his pains Wilhelm of Hesse-Cassel was placed under the Imperial ban. To add insult to injury his hated cousin, Georg of Hesse-Darmstadt, was made adminstrator of the sequestered lands. Only after his death was the indomitable Amalia Elizabeth able to reach an arrangement with the Emperor.
Relations between the French and Swedes remained unsettled. Both the treaties of Paris and Compiègnes remained unratified by Sweden.
Oxenstierna wished to negotiate a separate peace with the Emperor and extract himself from the German quagmire. He feared that a French alliance would tie his hands.
Oxenstierna had broached the subject with the Saxons but had received terms little better than a surrender at discretion. So he played for time, negotiating one treaty after another with Richelieu and ratifying none of them.
On 20 March, 1636, at Wismar in Mecklenburg, the Swedes and French reached another agreement. The French agreed to carry on the war in the Rhinelands and to pay the Swedes 1,000,000 livres to war in Silesia and Bohemia.
This treaty too remained unratified.
In an attempt to end the chaos in Germany, Pope Urban VIII declared a general meeting of the Catholic states in Cologne. Nobody came. The Habsburgs distrusted the Pope, known for his hatred of the House of Austria. The French, more intent on war than peace, refused to attend unless their heretical allies were admitted.
In September, 1636 the Swedes took the offensive again. Banér moved from his camp at Werben and down the Elbe towards Naumberg. A joint Saxon-Imperial force moved to stop the Swedes, whom they met at Wittstock in Brandenburg. On 4 October, 1636, the Swedes inflicted a crushing defeat on their more numerous foes.
The Swedes under Wrangel promptly occupied the remainder of Brandenburg, while Banér’s forces pushed as far as Eisenach. The Swedes were once more out of their Baltic redoubt.
Banér dispatched Wrangel against Brandenburg in an effort to overawe the Elector into alliance, as Gustavus had done five years before. The effort failed, and Georg-Wilhelm drew closer to the Emperor and began to raise an army of his own.
Banér and the Swedes moved south into Saxony, besieging Leipzig. The siege failed, and in January, 1637 they fell back on Torgau.
Ferdinand II convened a meeting of the Electors (Kurfürstentag) at Regensburg in the fall of 1636. As he had at the prior Electoral congress in 1630, he sought to have his son, Ferdinand of Austria, recognized as “King of the Romans,” heir-apparent to the Imperial throne.
In contrast to his earlier failure, on 22 December, 1636, the elder Ferdinand succeeded in having his son elected Roman King.
Soon after he had secured the inheritance of his throne, Ferdinand II sickened. On 15 February, 1636, he died in Vienna.
Since the French forces remained on the left bank of the Rhine, the Imperialists were able to concentrate their might against their Swedish opponents. Gallas was detached from the Rhine front and joined the Imperial forces in the northwest in a campaign against the Swedes.
Banér’s depleted army was badly overextended, and was outnumbered two-to-one by the Imperials. By misdirection and ambush he was able to elude the lumbering Gallas and escape to the sea. Nonetheless, by the end of 1637, the Swedes clung with difficulty to mere shreds of Pomerania.
In August, 1637, Bernhard crossed the Rhine. After defeating Johann von Werth at Ettenheim, he returned to the left bank of the river in September, with no real gains.
In the winter of that year he was to fare better. His first conquest came without a blow: the fortress Hohentweil in Würzberg had held out against the Imperials since Nördlingen. While Eberhard of Würzberg was willing to surrender it as the price of an Imperial pardon, its commander, Conrad Wiederholder, disagreed. He refused the order and in November, 1637 took service under Saxe-Weimar, bringing Hohentweil with him.
Saxe-Weimar proceeded to make himself master of the Forest Towns of the Rhine, most notably Rhinefelden. At this last place, he fought two bloody battles, losing the first. The second he won, capturing the opposing commander, the feared cavalry general Johann von Werth.
Saxe-Weimar was now in position to break Imperial power along the Rhine by taking the key to that power: the fortress of Breisach.