Brief as was the span of years embraced by the reign of the Catholic Kings it was as notable a period in intellectual progress as in other respects, bringing Spain into the current of modern life. This was due primarily to the rapid extension of printing, which had appeared in the peninsula in the closing years of the preceding period, and which now came into such general use that the works of Spanish and classical writers became available to all. Through private initiative many schools were founded which later became universities, although this activity was limited to Castile. Most notable of these institutions was that of Alcalá founded by Ximénez. This undertaking was due to the great cardinal’s desire to establish a Humanist centre of learning, where Latin, Greek, Hebrew, and philology could be studied to the best advantage. The most learned Spanish Humanists assembled there, together with many foreigners, and works of note were produced, such as the famous polyglot Bible in Hebrew, Greek, Chaldean, and Latin, with accompanying grammars and vocabularies. Not a little of the advancement in intellectual manifestations was due to the encouragement of the Catholic Kings, especially Isabella. Books coming into Spain were exempted from duty; ordinances were made regulating university life, and ridding it of much of its turbulence and abuses; and the court set an example in showing favor to distinguished scholars, who were engaged as teachers of the royal children. The great nobles imitated royalty, and invited foreign savants to Spain, among whom was the Italian, Peter Martyr of Anghiera, celebrated as the author of the first history of the Americas, the _De orbe novo_ (Concerning the new world). The most marked impulse to the spread of Humanist ideals came through Spaniards studying abroad, and these men returned to give Spain her leading names in intellectual production for the period. The greatest of them was Antonio de Nebrija, educated in Italy, a man of such encyclopedic attainments that he left works on theology, law, archæology, history, natural science, geography, and geodesy, although particularly noteworthy as a Latin scholar. Cardinal Ximénez is deserving of a high place in the achievements of the era for his patronage of letters, for it was through his aid that some of the most valuable work of the period was accomplished. Education was a matter for the higher classes only; people had not even begun to think, yet, of popular education. [Sidenote: Progress in the sciences.]