Sea in culture of barbarian invaders and knowledge of geography took a backward step. In the seventh century, Isidore of Seville produced a "wheel map" in which Asia, Africa and Europe were arranged like segments in an orange, separated by the "Mare Mediterranean", "Nilus" and "Tanais" and surrounded by "Oceanus". It was not until the fifteenth century that Ptolemy's maps were used again and Henry the Navigator of Portugal initiated ocean exploration and maritime research. Encouraged by him, Portuguese navigators explored, mapped and charted the west coast of Africa and the Eastern Atlantic and this knowledge prepared the way for the great voyages
Europe Cyprus and the Transcaucasian countries. A century ago, Europe had nearly a quarter of the world's population. The population of Europe has grown in the past century, but in other areas of the world (in particular Africa and Asia) the population has grown far more quickly. Among the continents, Europe has a relatively high population density, second only to Asia. Most of Europe is in a mode of Sub-replacement fertility, which means that each new(-born) generation is being less populous than the older. The most densely populated country in Europe (and in the world) is the microstate of Monaco. Pan