THIRTY
652
THIRTY
of the peculiar character of the problems he was to
solve. He did not dare to use his army for difficult
sieges or sudden attacks; where he was forced to do so
his projects failed. He left the strongly fortified city
of Magdeburg, which controlled the passage over the
Elbe, untaken in his rear. He wished to take by
storm in I\Ia>', 1628, the city of Stralsund, which
formed the connexion between the German Baltic
coast and Sweden, but he gave up this plan, and be-
sieged it from the land side. He could not force the city
to surrender, however, as Danish and Swedish troops
came to its aid. His victory in August, 1628, over
a Danish army of relief at Wolgast did not change the
result. Denmark, it is true, signed the Peace of
Lubeck, 22 May, 1629, on condition that all conquered
territoriesshouldbe
restored. But this
brought Gustavus
Adolphus on the
scene of war.
In the autumn of 1629, Gustavus .Adolphus declared before the Swedish Diet that the em- peror want ed to conquer Sweden and the Baltic, and that he should be prevented from do- ing so, but that if Sweden were vic- torious on German soil the German states would be- come the booty of Sweden. Up to this t ime, notwithstand- ing many offered inducements, the king had limited himself to wars with weaker opponents. He had, however, always carried on war, not only from love of it, but also from the necessity of sup- porting his army in foreign countries, as Swe- den, being a poor country, could not otherwise maintain it. In the meantime the king neglected nothing to increase the prosperity of Sweden. Just then he hoped to secure the wealth of the north German cities and princes. But now, the politico- commercial plans of the emperor threatened to put an end to Sweden's trade in copper, its one valuable natural source of wealth, while Wallenstein's troops threatened to expel the Swedish forces from the country beyond the Baltic, from the revenues of which, especially the customs, it largely drew its pecuniary means. Self-defence as well as the spirit of adventure forced the king to put some check upon the emperor. Nevertheless, he hesitated until the summer of 1630, when on 6 June he landed on the German coast of Pomerania. Except for a few persons of importance Gustavus was not wel- comed, even by the Protestants, and was obliged to make his way in Pomerania by force of arms. In a short time his money was entirely gone, and he debated for months whether he might venture inland. Wallenstein could, perhaps, have crushed him, but instead, he left tlie way open to him, for, through resentment at the emperor's command in the spring of 1630 to reduce the number of his troops, he had disbanded the greater part of the imperial forces in the districts now entered by Gustavus, and had allowed other detacOiments to be sent to fight in the Netherlands and Italy. The year previous Tilly had vainly begged Maximilian's permission to attack the Nctherlanders at the right moment in their own country, giving as his reason that the
money of the Dutch was constantly used to renew
the opposition to the Bavarian troops. Maximilian,
however, had not the courage to enter into open
conflict with a foreign foe. Thus the Dutch stadt-
holder, Frederick Henry, in 1629, after the great
Spanish general Spinola had been recalled, was able
to besiege Bois-le-Duc, and thus give the first great
rebuff to Spain. It was not Tilly who now hastened
to the aid of the Spaniards; an imperial force, de-
tached from Wallenstein's army, was sent. But
when the Dutch seized the fortification of Wesel and
thus endangered the retreat of the imperial troops,
a part of the imperial force fell back. Bois-le-Duc
surrendered on 14 September, and the Dutch were
able to take the offensive.
In France Richelieu had, from 1624 to 1628, re- established the internal authority of the govern- ment to such an extent that after twent}' years of cautious foreign policy more positive measures could be adopted. This change was first of all made evident to the Habsburgs in Lorraine. Duke Charles of Lorraine (from 1624), a vassal of the emperor, laid claim as heir to the Duchy of Barr in Alsace; but Richelieu disputed his rights and harassed the secular authority of the Bishop of Verdun so that the latter took refuge in the empire. In 1627 the male line of the Dukes of Mantua-Montferrat in upper Italy became extinct. The next heir was the Duke of Nevers, a relative of the Bourbons. He took possession at once of Mantua, and hoped to secure Montferrat also by the marriage of his son with the daughter of his predecessor, for the succession to Montferrat was in the female line. Montferrat, though, lay far below Mantua in the western part of upper Italy. Consequently Spain and Savoy were able to seize the district for themselves before the Duke of Nevers could enter it. Spain wished to maintain controlling influence in upper Italy, which it had acquired tluring the reign of Charles V. France, on the other hand, now saw Savoy, which had become dependent on it, suddenly taking sides with Spain. Spain asked for the decision of the emperor, who was suzerain of Mantua. Ferdinand interfered in the quarrel, not only because his dynasty had always considered the imperial rights in Italj' of much value, but also because he had constantly, from the time he ruled Styria, been opposed to Venice, which he believed might become dangerous. Still, neither he nor Spain carried on the negotiations rapidly nor with insistence, as their attention was claimed in other directions. Thus Richelieu had time to punish Savoy (1628-29). After this Ferdi- nand's troops besieged Mantua and the Spaniards under Spinola besieged Casale. Richelieu did not yet consider France strong enough to oppose the Habsburgs directly. When Mantua was taken and Casale's position became very precarious, Richelieu proposed a truce; this was signed at Rialto on 4 September, 1630. Then Richelieu sent his most adroit negotiator, Pere Joseph, to Ratisbon, where the electors were still in session. He hoped to withdraw France from the struggle but to raise up enemies enough against Austria elsewhere.
On 17 June, 1630, Richelieu made a treaty with the Netherlands by which he gave them a subsidy for the continuance of the war against Spain. By means of the truce, which was brought about by France, between Gustavus .Adolphus an<l Poland at Altmark in Sept(Mnb(<r, 1629, Gustavus was at liberty to take part in the war within the etu|iirc. .Nevertheless, he hesitated to a.ssume responsiliililies which would permit France to interfere with his management of the war. From March, 1629. negotiations had been actively carried on by Richelieu with the im|)erial estates but so far to little purpose. His aim was to separate them from tlieem|)eror by bringing them into a neutral confederation under his guidance. By
