At the time the two young Flemings were beginning work with their publishing operations, the independence of the Dutch Republic, though not yet formally acknowledged by Spain, was an assured fact, and the territory of the seven United Provinces was free alike from invaders and from civil strife. The Thirty Years’ War was, however (in 1618), just beginning in Germany, and until the peace of Westphalia, in 1648, the business connections of dealers in books with the book-trade centres in Frankfort, Leipzig, Cologne, etc., were, in common with all trade operations on the Continent, very much interfered with. The energy of the Dutch traders, however, repressed in one direction, found vent in another. Dutch fleets overcame the Spanish naval forces in the Pacific and transferred to the Dutch the control of many of the Spanish possessions in the East, while the trade between the Mediterranean and the North of Europe was largely transferred from Venice and Genoa to Amsterdam and Harlem. The devastation that had been brought upon Antwerp during the struggle with Spain, and the migration to the provinces of the North of thousands of the Protestants who had constituted a very important portion of the more intelligent and enterprising of the inhabitants of Flanders and Brabant, had helped to develop in the cities of the Dutch Republic the industries and the commerce of which Antwerp and Bruges had so long been the centre. While for a large part of Europe the Thirty Years’ War meant a throttling, or at least a serious hampering, of its trade, the commerce of the Dutch flourished behind the guns of their fighting vessels. With the expansion of the ambition and of the material resources of the new nation, came a rapid development of its intellectual activities and of the productive work of its scholars and writers. The Elzevirs had (as would naturally be the case with men who were exiles on the ground of their faith) associated themselves with the stricter and more earnest of the Calvinists of their adopted country. Bonaventure, the youngest of the sons of the first Louis, makes various references in his correspondence to the acceptance of and his cordial sympathy with the creed of the Calvinists as formulated by the Synod of Dort. The first publication which bore his individual imprint was a work of religious controversy bearing the rather ponderous title, _Censura ne Confessionem sive Declarationem Sententiæ eorum qui in Fœderato Belgio remonstrantes vocantur, super Præcipues Articules Christianæ Religionis, A. SS. Theol. Professoribus Academiæ Leidensis Instituta. 1626. Cum Privilegio._