The Renaissance (UK: , US: ) is a period in European history, covering the span between the 14th and 17th centuries. It is an extension of the Middle Ages, and is bridged by the Age of Enlightenment to modern history. It grew in fragments, with the very first traces found seemingly in Italy, coming to cover much of Europe, for some scholars marking the beginning of the modern age. The intellectual basis of the Renaissance was its own invented version of humanism, derived from the concept of Roman Humanitas and the rediscovery of classical Greek philosophy, such as that of Protagoras, who said that "Man is the measure of all things." This new thinking became manifest in art, architecture, politics, science and literature. Early examples were the development of perspective in oil painting and the recycled knowledge of how to make concrete. Although the invention of metal movable type sped the dissemination of ideas from the later 15th century, the changes of the Renaissance were not uniformly experienced across Europe. As a cultural movement, the Renaissance encompassed innovative flowering of Latin and vernacular literatures, beginning with the 14th-century resurgence of learning based on classical sources, which contemporaries credited to Petrarch; the development of linear perspective and other techniques of rendering a more natural reality in painting; and gradual but widespread educational reform. In politics, the Renaissance contributed to the development of the customs and conventions of diplomacy, and in science to an increased reliance on observation and inductive reasoning. Although the Renaissance saw revolutions in many intellectual pursuits, as well as social and political upheaval, it is perhaps best known for its artistic developments and the contributions of such polymaths as Leonardo da Vinci and Michelangelo, who inspired the term "Renaissance man". The Renaissance began in Florence, Italy, in the 14th century.