The student of Spanish letters is aware that the Golden Age was a period of great writers and intensive cultivation of literature; not always is he equally familiar with the fact that the period underwent a series of numerous and profound changes both literary and social. This paper aims at explaining some of these changes. The few decades which immediately preceded her Golden Age had seemed to promise a future of increasing power and wealth for Spain. With the marriage of Ferdinand and Isabel in 1469 unified rule was established in the nation for the first time in centuries. Control of the Aragonese possessions in Italy gave the country important foreign outposts. The expulsion of the Moors in 1492 paved the way for the discovery of America with its potentialities for great wealth as well as political and religious expansion. When young King Carlos, the grandson of Ferdinand and Isabel, became Holy Roman Emperor in 1519, optimistic views that the nation had been chosen by Providence to assume the leadership of the Christian world seemed to be justified., The Golden Age was a period of change and upheaval, characterized by animation, restlessness and instability. The development of such heterodox groups as the alumbrados, who rejected the sacraments and other precepts of the Church, and the erasmistas, who cared little for the supernatural element in religion, during the reign of Carlos V, and the Baroque art of a few decades later are manifestations of the prevailing restlessness of spirit. One phase of this spirit was positive in nature, and expressed itself in an outburst of great intellectual activity. One need only mention four of the outstanding writers of the age-Cervantes, Lope de Vega, Quevedo and Calder6n-to give an indication of the productiveness and excellence which can be noted in its men of letters. Dramas were written by the hundreds, realistic fiction experienced a remarkable development, and writers on mystic subjects alone are said to have numbered more than three thousand. Between 1472 and 1572 twenty universities were founded in the nation. Equally impressive were Spain's contributions in geography, astronomy, mathematics, navigation and allied fields. The Golden Age began just when a change of major proportions was taking place in Spanish literature-the naturalization of the Italian eleven-syllable verse by Boscain and the introduction of such new Italian strophes as the sonnet, cancidn, octava real and tercetos. With the passage of time, other changes in literary style and taste can be noted. The five acts of Torres Naharro had been reduced to three by 1600. The picaresque novel and the pastoral romance developed in the sixteenth century, while the seventeenth century saw the wide acceptance of culteranismo and conceptismo, with their cultivated obscurity of style and thought. Especially striking were the changes that took place in the strophes used by dramatists starting with the year 1575. We are now on the threshold of a decade which witnessed abrupt and complete revolution in dramatic versification. The suddenness of these changes is indeed amazing and apparently without due preparation.2 The desire for change in this dynamic,