The Renaissance of the 12th century was a period of many changes at the outset of the High Middle Ages. It included social, political and economic transformations, and an intellectual revitalization of Western Europe with strong philosophical and scientific roots. These changes paved the way for later achievements such as the literary and artistic movement of the Italian Renaissance in the 15th century and the scientific developments of the 17th century. Medieval renaissances The groundwork for the rebirth of learning was laid by the process of political consolidation and centralization of the monarchies of Europe. This process of centralization began with Charlemagne, King of the Franks from 768 to 814 and Holy Roman Emperor from 800 to 814. Charlemagne's inclination towards education, which led to the creation of many new churches and schools where students were required to learn Latin and Greek, has been called the Carolingian Renaissance. A second "renaissance" occurred during the reign of Otto I (The Great), King of the Saxons from 936 to 973 and Emperor of the Holy Roman Empire from 962. Otto was successful in unifying his kingdom and asserting his right to appoint bishops and archbishops throughout his kingdom. Otto's assumption of this ecclesiastical power brought him into close contact with the best educated and most able class of men in his kingdom. Because of this close contact many new reforms were introduced in the Saxon Kingdom and in the Holy Roman Empire. Thus, Otto's reign has been called the Ottonian Renaissance. Therefore, the Renaissance of the 12th century has been identified as the third and final of the medieval renaissances. Yet the renaissance of the twelfth century was far more thoroughgoing than those renaissances that preceded in the Carolingian or in the Ottonian periods. Indeed, the Carolingian Renaissance was really more particular to Charlemagne himself, and was really more of a "veneer on a changing society" than a true renaissance springing up from society, and the same might be said of the Ottonian Renaissance. Historiography The Harvard professor Charles Homer Haskins was the first historian to write extensively about a renaissance that ushered in the High Middle Ages starting about 1070. In 1927, he wrote that: The English art historian Kenneth Clark wrote that Western Europe's first "great age of civilisation" was ready to begin around the year 1000. From 1100, he wrote, monumental abbeys and cathedrals were constructed and decorated with