As long as Gustavus Adolphus lived there was but little room for Richelieu in German politics. Had he survived a few years longer, it is not improbable that the world would have seen an alliance of the Moderates in Germany, under the leadership of Richelieu, supported possibly by both Maximilian and Wallenstein, against the Emperor and the king of Sweden. But the death of Gustavus quickly put the decisive voice in German affairs into the possession of France. Already in 1632 French troops had appeared upon the Rhine, and garrisoned the new fortress of Ehrenbreitstein at the invitation of the elector of Trier. In the same year Richelieu became a party to the League of Heilbronn, and so secured the right to interfere in German affairs. In 1633 a French army entered the old German territory of Lorraine and captured its capital Nancy, owing to the incessant intrigues against the all-powerful cardinal of which the duke had been guilty. The battle of Nördlingen in 1634 put Protestant Germany at the feet of Richelieu. The soil of Germany, harried and plundered, could with difficulty sustain the armies which devastated it. Sweden, poor and exhausted, could make no sacrifices. England was too much occupied with pecuniary difficulties at home to be able to send assistance to Germany. [Sidenote: =Declaration of war against Spain, 1635.=] France was the only power both able and willing to provide the sinews of war. She became the protector and director of the League of Heilbronn, took Bernhard of Saxe-Weimar and his army into her pay, claimed from the Swedes the custody of the fortresses held by them in Alsace, and on 19th May 1635 formally declared war against Spain. [Sidenote: =The character of the war altered by French interference.=]