The Rhinegrave Otto, who was commanding in Elsass for the confederates, in the same way effected his retreat, delivering over to Marshal La Force Colmar, Schlestadt, and many small places; the Bishop of Basle and the free city of Mulhausen likewise claimed French protection.
On the 1st of November, the ambassadors of Sweden and of the Protestant League signed at Paris a treaty of alliance, soon afterwards ratified by the diet at Worms, and the French army, entering Germany, under Marshals La Force and Breze, caused the siege of Heidelberg to be raised on the 23d of December.

Richelieu was in treaty at the same time with the United Provinces for the invasion of the Catholic Low Countries.

It was in the name of their ancient liberties that the cardinal, in alliance with the heretics of Holland, summoned the ancient Flanders to revolt against Spain; if they refused to listen to this appeal, the confederates were under mutual promises to divide their conquest between them.

France confined herself to stipulating for the maintenance of the Catholic religion in the territory that devolved to Holland.

The army destined for this enterprise was already in preparation, and the king was setting out to visit it, when, in April, 1635, he was informed of Chancellor Oxenstiern's arrival.