If it is difficult to date the starting point of a common European world, the collapsing Roman Empire was certainly its melting pot. At the beginning of the Middle Ages, Europe was already born divided between the eastern empire, which would continue with Byzantium for a millennium, and the western one, which was dissolved by the great migrations of peoples and gave way to numerous barbarian states with fluid borders. The fragmentation would be consolidated with the permanent settlement and territorial formation of peoples, from which the modern nation-states would emerge after the 14th century. The attempts of powerful rulers (from Justinian and Charlemagne to Charles V) to restore the lost imperial unity would be succeeded by efforts to unify the continent under the dominance of one nation (undertaken by Philip II, Ferdinand II, Napoleon). However, these hegemonic ventures always encounter the resistance of other peoples and nations, which favor a European balance. Paradoxically, the fragmentation does not prevent the emergence, already from the Middle Ages, of a European identity, founded on the one hand on Greco-Roman culture, which bequeaths to Europe Greek thought, Roman state and legislative models, and the vision of a universal empire, and on the other hand on the Christian religion, which appears through the Church as a cohesive element of societies. This common identity is evidenced by a series of developments that ignore borders: barbarian invasions, contraction and then expansion of exchanges, extensive clearings, manorial vitality, transition from handicrafts to industry, papacy, orthodoxy and heresies, Protestant Reformation and Roman Catholic Counter-Reformation, philosophical movements of humanism and enlightenment, artistic currents of the Renaissance, Baroque and Classicism, establishment of the scientific spirit, radiance of the ideas of the French Revolution... Alongside the Europe of states, a Europe of merchants, bankers, monks, artists, or scholars is formed, which, at the dawn of the 19th century, opens the doors to the future. [Excerpt from a publisher or edition presentation text]