Chapel at Glendalough, south of Dublin, Ireland The monastery complex, begun in the 6th Century, became one of the intellectual centers of Ireland until 1214 AD. It seems to have been customary in the Celtic churches of early times, in Ireland as well as in Scotland, to keep Saturday, the Jewish Sabbath, as the day of rest from labor. [previous document] [back to Index] [next document] [Approaching the End] .