Between the 10th and 13th centuries, a new artistic aesthetic emerged in the Christian kingdoms of the northernmost part of the Iberian Peninsula. This first international European style was given the name of Romanesque, owing to the aim to recover some of the political and cultural unity of the ancient Roman Empire, in this case under the spiritual guidance of the Christian Church: the artistic and spiritual conception of the French abbey of Cluny was essential for its development. Roman semi-circular arches were recovered as one of its defining characteristics - together with barrel vaults, sculptures on doors, façades, capitals and modillions, and the use of unpolished squared stones. In Spain, architecture and other arts embarked on a period of prodigious development and were enriched by a range of very diverse characteristics, influenced by the arrival of craftsmen from different countries –primarily France and Lombardy– along the Way of Saint James, as well as by the closeness to the Muslim world and the underlying native cultural elements.