On the other hand so long as petty wars persisted the enslavement of captives continued to be at least sporadic, particularly in the south and east of Europe, and a considerable traffic in white slaves was maintained from east to west on the Mediterranean.

The Venetians for instance, in spite of ecclesiastical prohibitions, imported frequent cargoes of young girls from the countries about the Black Sea, most of whom were doomed to concubinage and prostitution, and the rest to menial service.[7] The occurrence of the Crusades led to the enslavement of Saracen captives in Christendom as well as of Christian captives in Islam.
[Footnote 7: W.C.Hazlitt, _The Venetian Republic_( London, 1900), pp.

81, 82.] The waning of the Crusades ended the supply of Saracen slaves, and the Turkish capture of Constantinople in 1453 destroyed the Italian trade on the Black Sea.

No source of supply now remained, except a trickle from Africa, to sustain the moribund institution of slavery in any part of Christian Europe east of the Pyrenees.

But in mountain-locked Roussillon and Asturias remnants of slavery persisted from Visigothic times to the seventeenth century; and in other parts of the peninsula the intermittent wars against the Moors of Granada supplied captives and to some extent reinvigorated slavery among the Christian states from Aragon to Portugal.
Furthermore the conquest of the Canaries at the end of the fourteenth century and of Teneriffe and other islands in the fifteenth led to the bringing of many of their natives as slaves to Castille and the neighboring kingdoms.
Occasional documents of this period contain mention of negro slaves at various places in the Spanish peninsula, but the number was clearly small and it must have continued so, particularly as long as the supply was drawn through Moorish channels.