By the 12th century Clonmacnoise began to decline. The reasons were varied, the Vikings under Turgesius and the Normans attacked. Without doubt the most debilitating factor was the growth of the town of Athlone to the north of the site from the late-12th century. Athlone became the main trading town for the midlands of Ireland, the most popular route for crossing the Shannon, as well as the best-defended settlement in the region. People migrated north from Clonmacnoise to Athlone, and with the fall in population went much of the support that the site needed to survive, and former allies began to recognise the decline in the site's influence. The influx of continental religious orders such as the Cistercians, Franciscans, Augustinians, Benedictines, Cluniacs, etc. around the same time fed into this decline as numerous competing sites began to crop up. Ireland's move from a monastic framework to a diocesan one in the twelfth century similarly diminished the site's religious standing, as it was designated the seat of a small and impoverished diocese.