The growth however of English commerce far outstripped as yet that of its manufactures. We must not judge of it by any modern standard; for the whole population of the country can hardly have exceeded five or six millions, and the burthen of all the vessels engaged in ordinary commerce was estimated at little more than fifty thousand tons. The size of the vessels employed in it would nowadays seem insignificant; a modern collier brig is probably as large as the biggest merchant vessel which then sailed from the port of London. But it was under Elizabeth that English commerce began the rapid career of developement which has made us the carriers of the world. The foundation of the Royal Exchange at London by Sir Thomas Gresham in 1566 was a mark of the commercial progress of the time. By far the most important branch of our trade was the commerce with Flanders. Antwerp and Bruges were in fact the general marts of the world in the early part of the sixteenth century, and the annual export of English wool and drapery to their markets was estimated at a sum of more than two millions in value. But the religious troubles of the Netherlands were already scaring capital and industry from their older seats. As early as 1560 Philip's envoy reported to his master that "ten thousand of your Majesty's servants in the Low Countries are already in England with their preachers and ministers." Alva's severities soon raised the number of refugees to fifty thousand; and the outbreak of war which followed drove trade as well as traders from the Low Countries. It was with the ruin of Antwerp at the time of its siege and capture by the Duke of Parma that the commercial supremacy of our own capital was first established. A third of the merchants and manufacturers of the ruined city are said to have found a refuge on the banks of the Thames. The export trade to Flanders died away as London developed into the general mart of Europe, where the gold and sugar of the New World were found side by side with the cotton of India, the silks of the East, and the woollen stuffs of England itself. [Sidenote: New trade routes.]