Sully encouraged agriculture, urged the free circulation of produce, promoted stock-raising, forbade the destruction of the forests, drained swamps, built roads and bridges, planned a vast system of canals and actually began the Canal de Briare. He strengthened the French military establishment; under his direction, the construction of a great line of defences on the frontiers began. Abroad, Sully opposed the king's colonial policy as inconsistent with French interests, in opposition to men like Champlain who urged greater colonial efforts in Canada and elsewhere. Neither did Sully show much favor toward industrial pursuits but, on the urgent solicitation of the king, he established a few silk factories. He fought together with Henry IV in Savoy (1600–1601) and negotiated the treaty of peace in 1602; in 1603, he represented Henry at the court of James I of England; and throughout the reign, he helped the king to put down insurrections of the nobles, whether Roman Catholic or Protestant. It was Sully, too, who arranged the marriage between Henry IV and Marie de' Medici.