In Europe the old pagan slavery existed in many nations, and in the early Christian centuries underwent many modifications through the advance of the new religion and civilization. The modern form of slavery began with the first importation of negroes into Europe, as shown in the following account, from which it appears that the history of modern slavery begins with the history of African discovery. Petrarch is referred to by Viera to prove that the Genoese sent out an expedition to the Canary Islands. Las Casas mentions that an English or French vessel bound from France or England to Spain was driven by contrary winds to these Islands, and on its return spread abroad in France an account of the voyage. The information thus obtained--or perhaps in other ways of which there is no record--stimulated Don Luis de la Cerda, Count of Clermont, great-grandson of Don Alonzo the Wise of Castile, to seek for the investiture of the crown of the Canaries, which was given to him with much pomp by Clement VI, at Avignon, in 1344, Petrarch being present. This sceptre proved a barren one. The affairs of France, with which state the new King of the Canaries was connected, drew off his attention; and he died without having visited his dominions. The next authentic information that we have of the Canary Islands is that, in the times of Don Juan I of Castile, and of Don Enrique, his son, these islands were much visited by the Spaniards. In 1399, we are told, certain Andalusians, Biscayans, Guipuzcoans, with the consent of Don Enrique, fitted out an expedition of five vessels, and making a descent on the island of Lanzarote, one of the Canaries, took captive the King and Queen, and one hundred and seventy of the islanders.