The pattern of trade which characterised late-medieval Scotland continued through much of the sixteenth century. Scotland’s export trade was heavily dependent on wool, woollen cloth, hides and fish. From a low level in the early sixteenth century Scottish trade expanded in the 1530s, slumped during the English invasions of the 1540s, then grew in the second half of the century to reach a peak during the 1620s and 1630s. The evidence for this expansion is fragmented but the overall trend is clear. The rapid rise in coal exports, especially from the 1590s, was paralleled by the growth of the salt industry. Production of lead ore, though far smaller in quantity, may not have been far behind coal in terms of value. An expansion of industrial output is also demonstrated indirectly by rising imports of raw materials like iron, timber and flax. Shipments of iron from the Baltic more than trebled between the 1570s and the 1630s while those of flax and hemp doubled. 1