At the time of the Reformation in the 1560s Scotland and the Netherlands already had long-established commercial links. Scots soldiers fought in the wars that ravaged the Low Countries and much of northern Europe in the two centuries after Calvinism gained a foothold. Goods, people, and ideas were readily exchanged in the North Sea basin. With the foundation in 1575 of the avowedly Protestant University of Leiden, academic and intellectual intercourse were added to trading ties. By the mid-seventeenth century Leiden had an international reputation for legal and medical education. Expatriate Protestant churches were established in the early seventeenth century, notably the Scots kirk, Rotterdam. There were nineteen English and Scottish religious communities in the Dutch Republic by the end of the seventeenth century.