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. Louis XIII. awaited him at Compiegne. The chancellor was accompanied by a numerous following, worthy of the man who held the command of a sovereign over the princes of the Protestant League; he had at his side the famous Hugo Grotius, but lately exiled from his country on account of religious disputes, and now accredited as ambassador to the King of France from the little queen, Christina of Sweden. It was Grotius who acted as interpreter between the king and the chancellor of Sweden. A rare and grand spectacle was this interview between, on the one side, the Swede and the Hollander, both of them great political philosophers in theory or practice, and, on the other, the all-powerful minister of the King of France, in presence of that king himself. When Oxenstiern and Richelieu conferred alone together, the two ministers had recourse to Latin, that common tongue of the cultivated minds of their time, and nobody was present at their conversation. Oxenstiern soon departed for Holland, laden with attentions and presents: he carried away with him a new treaty of alliance between Sweden and France, and the assurance that the king was about to declare war against Spain.