Ireland, Scotland and Wales were all Celtic countries, but their respective medieval populations did not know this and their Celticity is not the reason for grouping them together. The tenth century Dublin-York axis brought commercial urbanism to Ireland, the eleventh-century kings used its resources to fund their ambition to rule the entire island of Ireland, and this great struggle was the leitmotiv of Irish history until the Norman attack. Monasteries formed federations in the late seventh and eighth centuries. Society is seen, from an aristocratic perspective, in class terms: kings, lords and commons. In 700 the kingdom of Scotland was occupied by three peoples, Dál Riata, Britons of Strathclyde and Picts, and under pressure from a fourth, the Northumbrians. In Wales rex is the universal term for king, in literature and epigraphy. Like Ireland, Wales was raided from the Irish Sea. In the eleventh century, Wales became an unstable land of unresolved segmentary struggles and quick-moving dynastic warfare.