Irishtown grew outside of Dublin, about 2,000 metres west of the medieval city walls (see also Ringsend). Dublin was originally a Viking city and after 1171, when an Anglo-Norman army seized it, Dublin became the centre of English rule in Ireland. The native Gaelic Irish were therefore viewed as an alien force in the city, and suspicion of them was deepened by continual raids on Dublin and its environs by the O'Byrne and O'Toole clans from the nearby Wicklow Mountains. By the 15th century, Gaelic migration to the city had made the English authorities fearful that English language and culture would become a minority there. As a result, the Irish inhabitants of Dublin were expelled from the city proper in about 1454, in line with the Statutes of Kilkenny. The Irish population were only allowed to trade inside the city limits by daylight. At the end of the day's trading, they would leave and set up camp in what was to become known as the Irishtown.