In the face of the growing resistance the duke of Alva strongly advised Philip II to convert the towns into fortresses.[944] For the Flemish cities were, as yet, commercial groups, not fortified burgs. With the possible exception of Gravelines, no one of them was capable of making a sustained defense. This suggestion happened to coincide with the English occupation of Havre-de-Grace and the possible return of Calais to England in return therefor. Such a contingency could but be viewed with anxiety by Spain,[945] and this fact, coupled with the uncertainty of developments in France induced Philip to follow out Alva’s suggestion by strengthening Gravelines. France at once became alarmed over Calais and protested in the same breath against the building of fortifications at Gravelines and the duty upon her wines.[946] In retaliation the French government also strengthened the garrisons on the edge of Picardy, under the direction of the prince of Condé (who was governor of the province), to the immense indignation of Spain.[947] The Spanish erections around Gravelines reacted also upon the state of things in Flanders. For new and heavier taxation was the indispensable point of departure for carrying out such measures, “unless one were willing to see everything said upon the subject vanish in smoke.” The sole effective remedy for the state of things prevailing in the Flemish provinces was, of course, to reorganize the finances and the administration of justice in accordance with the demands made by the nobles. But instead of attempting to do this, the government aimed to weaken the opposition by dividing the leaders, and the long silence of Philip II covered an attempt to draw away Egmont, who was regarded as the ringleader of the Flemish nobles at this time.[948] The Spanish government dreaded to summon the estates, as Orange insisted should be done, for fear of things in Brabant and the other provinces going the road of things in France under like conditions.[949] In order, therefore, to provide for funds without asking the estates to vote subsidies, over which there was sure to be a conflict, the Spanish government in the Netherlands undertook to raise the needed money by tariffs. The cloth trade of England and the wine trade of France were the two commodities so taxed. In 1563 a duty was laid on French wine.[950] In the case of England, the excuse given for the high duty placed on imported cloth was precaution against the plague.[951] France at once protested against the tariff and threatened to retaliate by taxing the herring and cod trade, though the Spanish ambassador at Paris represented that such action would entirely destroy the wine trade and would compel reprisal.[952]