Direct English and Scottish interest in Mediterranean affairs began with the possibilities of trade and profit. The territorial advances of the Ottoman Empire in the Eastern Basin caused great disruption to the Italian cities’ trading systems, at first particularly that of Genoa, later of Venice, as the cities found themselves on the wrong side at various times in the frequent Ottoman wars. In the 1450s (about the time the Turks finally captured Constantinople) one British merchant, Robert Sturmy of Bristol, had attempted to trade there, carrying wool, cloth, tin, and wheat to Italy and the Levant, and purchasing spices and silk, and alum, in exchange – in effect copying the Venetian system in reverse. However, his two ventures both ended in disaster. In the first, his ship, having delivered 200 pilgrims to Jaffa in Palestine, was wrecked on the Greek coast on the return voyage; in the other, his ship was intercepted and looted by Genoese ships who disliked the competition; Sturmy was killed in the fighting. This seems to have deterred other ventures, but also pointed up the possibilities. By the end of the fifteenth century voyages by English merchants to Italy and the Eastern Basin – to Crete and the Levant – were frequent enough for a consul to be appointed to Pisa by King Henry VII. This was a port city subject to Florence, and so it was outside the range of hostility from Genoa and Venice; there were English merchants in several other Mediterranean ports at this time also.

The voyage to the Mediterranean lay past Portugal and Spain, and in both countries there was a longstanding English political and mercantile connection. An alliance of sorts between England and Portugal had existed since 1398, but the connection went back to the Second Crusade centuries earlier; in Spain there was a fluctuating presence of English merchants, particularly in the Andalusian area, since the fourteenth century, centred on Seville, its outport of San Lucar, and at Cadiz. There, they knew of the discovery and settlement of the Canary Islands from the 1390s. English traders were familiar with the islands, where some settled and bought estates, and with Madeira, which was settled from Portugal in the mid-fifteenth century, eventually to be the source of sugar and a much-appreciated wine.