See Weidmann, Geschichte der Bibliothek von St Gallen; St Gall, 1841.
This manuscript was formerly believed to have been once in the possession of Saint Augustine, but it is clearly a good deal later in date than his time.
Eventually there were three Norse kingdoms in Ireland, the capitals of which were Dublin, Waterford and Limerick; and the three chief ports of Ireland, Dublin, Cork and Belfast were all founded by the Viking invaders; see C. F. Keary's valuable work, The Vikings in Western Christendom, London, 1891, pp. 165 to 185.
The blessing in the Greek Church is given by raising three fingers; in the Western Church two fingers and the thumb are used.
See Westwood, Miniatures of Irish Manuscripts, London, 1868, Pl. I. and II.