t once signed a treaty with the Swedes,
agreeing to grant them large subsidies to carry on the war. By a similar
treaty he promised subsidies and the province of Alsace to the Duke of
Saxe-Weimar. He entered into an arrangement with the Dutch, who were to
aid France to conquer Flanders, which was to be divided between the two
powers; while the Dukes of Savoy, Parma, and Mantua agreed to undertake,
in alliance with France, the invasion of Milan, and to receive in return
a portion of the territory won from Spain. At the same time France
declared war against Spain. It was to the army commanded by Cardinal
de la Valette, which was to act with that of Saxe-Weimar against the
Imperialists, that Turenne was attached.

The campaign began unfavourably. The impetuosity of Saxe-Weimar, who
hoped to recover his own principality, induced Valette to cross the
Rhine; but he was forced to retire in all haste, and the army suffered
terribly in the retreat. Turenne was in command of the advanced
guard, and his courage and activity alone saved the army from complete
destruction--seizing upon defiles, overthrowing the enemy who barred
the passages, and enabling the army to recross the Rhine with numbers
diminished only by sickness, fatigue, and hunger. At the siege of
Saverne, Turenne led the French troops to the attack after three
repulses, and succeeded in gaining a footing in the town, but received
himself a very severe wound in the arm with a musket ball. During the
following year several towns were captured but no decisive operations
took place.

In 1638, the Duke of Saxe-Weimar gained some great successes, defeated
the Imperialists with heavy loss at Rheinfelden, and besieged Breisach,
the key of southern Germany. The Imperialist army marched to relieve
the place, but reinforcements were sent from France under the command
of Turenne and Longueville. Three battles were fought and the Austrians
driven off. After an assault by Turenne, Breisach capitulated, and
all Alsace had now fallen into the hands of Saxe-Weimar. Having been
promised Alsace he refused, as Richelieu desired, to hand over Breisach
to France; but on the death of the duke in the following year, Richelieu
bought over his lieutenants, the French flag waved over the towns of
Alsace, and the Upper Rhine became the French frontier. Turenne returned
to court, where he was received with enthusiasm, and was a short time
afterwards ordered to Italy to assist De la Valette, who