The House of Hapsburg reaped undeserved advantages from Wallenstein's death. His army passed under the command of the emperor's son, Ferdinand, king of Hungary. It was joined by the Spanish troops from Italy, which Wallenstein had tried to exclude. Thus strengthened it advanced to the relief of Bavaria, where the troops of the Heilbronn League were wholly inferior. At Nordlingen, Bernhard of Saxe-Weimar induced his cautions colleague Horn to risk a battle, in which they were wholly routed and Horn taken prisoner (September, 1634). Nordlingen did for the Catholics of the south what Breitenfeld had done for the. Protestants of the north. The work of Gustavus was undone, and almost the whole of Southern Germany fell into the hands of the imperialists.
The first great result of the battle of Nordlingen was to throw the defeated Protestants into the arms of France. Richelieu's object was at last obtained, and French influence tends to supplant that of Sweden. Oxenstiern was forced to cede the fortresses of Elsass to France, and thus to commence that dismemberment of the empire, which Gustavus had hoped to avoid. War between France and Spain was declared in 1635. Another great result of the battle was the treaty of Prague. John George of Saxony was more than ever averse to the war. If he hail been jealous of the Swedes, he was far more so of the French. The negotiations which Wallenstein's death had interrupted, were resumed. Ferdinand had learnt some wisdom from adversity, and was willing to give up in fact, though not in word, the Edict of Restitution. The year 1627 was to replace 1552. All bishoprics held by Protestants at that date were to remain in their hands. The Calvinism were excluded from the treaty, which could not therefore be permanently satisfactory. Such as it was, however, it was accepted by most of the Protestant states, and the great conflict might have ended in 1635, but for the foreign interests that had become involved in it.