So it was that through a combination of causes the prospects of peace suddenly darkened just as Wolsey was preparing to stand forward as the mediator of Europe. Doubtless he hoped, when first he put forward the project of a conference, that it might be the means of restoring his original design of 1518, a European peace under the guarantee of England. Since that had broken down he had been striving to maintain England's influence by separate alliances; he hoped in the conference to use this position in the interests of peace. But first of all the alliance with the Emperor must be made closer, and the Emperor showed signs of demanding that this closer alliance should be purchased by a breach with France. If war was inevitable, England had most to gain by an alliance with Charles, to whom its friendship could offer substantial advantages, as England, in case of war, could secure to Charles the means of communicating between the Netherlands and Spain, which would be cut off if France were hostile and the Channel were barred by English ships. Moreover the prospect of a marriage between Charles and the Princess Mary was naturally gratifying to Henry; while English industry would suffer from any breach of trading relations with the Netherlands, and the notion of war with France was still popular with the English. So Wolsey started for Calais at the beginning of August with the intention of strengthening England's alliance with the Emperor, that thereby England's influence might be more powerful. Charles on the other hand was resolved on war; he did not wish for peace by England's mediation, but he wished to draw England definitely into the league between himself and the Pope against France. Wolsey knew that much depended on his own cleverness, and nerved himself for the greatest caution, as Francis was beginning to be suspicious of the preparations of Charles, and the attitude of affairs was not promising for a pacific mediation. This became obvious at the first interview of Wolsey with the imperial envoys, foremost amongst whom was Gattinara. They were commissioned to treat about the marriage of Charles with the Princess Mary, and about a secret undertaking for war against France; but their instructions contained nothing tending to peace. The French envoys were more pacific, as war was not popular in France.