nce it was clear that substantial landmasses lay in the way of access to spice-rich Asia, it was inevitable that efforts would be made to find a way around them. Sebastian Cabot, who had been to Newfoundland, was determined to find a northwest passage. His voyage of 1508-09 brought him into Hudson Strait, but he was forced to return. In the Spanish service (1512-48) he was unable to make further attempts, though he kept alive his belief in a passage. Between 1509 and 1576 a few abortive attempts were made to find an opening to the West, and there was much discussion in England between 1515 and 1541, but no results. Meantime, globes made in Europe tended to show such a passage from 1520 onwards. Indeed, apparently authoritative maps by Mercator and Ortelius in 1569 and 1570 clearly showed such a passage. Humphrey Gilbert was planning a voyage from 1565, but his theoretical justification (written 1566) for such a voyage was not published until 1576. By then Martin Frobisher and Michael Lok had revived plans for a voyage. In 1576 they were able to send two ships, followed by further expeditions in the two following years. This paper provides a brief historical introduction to the exploration efforts that preceded the Frobisher voyages.