The chief exports were furs, horses, wool, and fish while the imports consisted chiefly in articles of luxury, whether for clothing or ornament. There was an extensive trade with the Orient in all such luxuries and the Vikings seem eagerly to have accumulated wealth of this kind. When Limerick was re-captured by the Irish in 968, they carried off from the Vikings 'their jewels and their best property, and their saddles beautiful and foreign (probably of Spanish workmanship), their gold and their silver: their beautifully woven cloth of all colours and all kinds: their satins and silken cloths, pleasing and variegated, both scarlet and green, and all sorts of cloth in like manner.' They captured too 'their soft, youthful, bright, matchless girls: their blooming silk-clad young women: and their active, large, and well formed boys.' Such captives whether made by Irish from Norsemen or Norsemen from Irish would certainly be sold as slaves, for one of the chief branches of trade in those days was the sale as slaves of those made prisoner in war. The expansion of Scandinavian trade took place side by side with, rather than as a result of, Viking activity in war. There is evidence of the presence of traders in the Low Country early in the 9th century, and already in the days of St Anskar we hear of a Swedish widow of Björkö who left money for her daughter to distribute among the poor of Duurstede. Jómsborg was established to protect and increase Scandinavian trade at Julin, and there were other similar trading centres on the southern and eastern shores of the Baltic. The Viking might busy himself either with war or trade, but whatever his occupation, living as he did in insular or peninsular lands, good ships and good seamanship were essential to his livelihood. Seamen now often abandoned that timid hugging of the coast, sailing only by day time and in fair weather, which characterised the old Phoenician traders, and boldly sailed across the uncharted main with no help save that of the sun and stars by which to steer their course. It was this boldness of spirit alone which enabled them to reach the lonely Faroes, the distant Shetlands and Orkneys, and the yet more remote Iceland. Irish monks and anchorites had shown similar fearlessness, but their bravery was often that of the fanatic and the mystic rather than the enterprise of the seaman. Boldness of seamanship led to boldness in exploration. From Iceland the Vikings sailed to Greenland, and by the year 1000 had discovered Vinland, the N.E. part of North America. Ottarr rounded the North Cape and sailed the White Sea in the 9th century, while Harold Hardrada in the 11th century made a voyage of Polar exploration.