So far as literature and art are concerned, the period of the Viking occupation is one of the most interesting in the history of Ireland. In spite of the destruction of the monasteries and the departure of numbers of the monks[81] to the Continent the work of the great schools was carried on and there was considerable literary activity;[82] in 914 and 924, respectively, the great crosses at Clonmacnois and Monasterboice were set up; cumhdachs, or book-shrines of plated gold and silver, were made for the three great manuscripts, the _Book of Kells_, the _Book of Durrow_ and the _Book of Armagh_; carved gold, silver, and bronze work reached a high level of excellence in the famous Ardagh Chalice and the Tara Brooch; and during the years which intervened between the battles of Gleann Mama and Clontarf, Romanesque architecture was introduced into Ireland. Irish art did not remain wholly free from Scandinavian influence. In the Cross of Cong (A.D. 1123) the Celtic interlaced patterns are found side by side with the “worm-dragon” ornament, while the crosier of Clonmacnois, the psalter of Ricemarsh and the shrine of St. Patrick’s Bell are decorated in the style known as “Hiberno-Danish.”[83] The Vikings, on the other hand, came under the influences of Irish art and literature. We find marks of Celtic influence not only in the sculptured crosses erected by the Norsemen in the North of England and Man, but even in Scandinavia itself.[84] Moreover, there are strong reasons for supposing that the rise of the prose saga among the Icelanders may be the outcome of their intercourse with the Irish in the ninth and tenth centuries. FOOTNOTES [40] _Annals of Ulster_, A.D. 855, 856; _Annals of the Four Masters_, A.D. 856. [41] _Three Fragments of Annals_, pp. 128, 129, 138, 139. [42] _Airec Menmam Uraird Maic Coisse_, sec. 29 (Marstrander: _Bidrag til det Norske Sprogs Historie i Irland_, p. 10). [43] With the Gaill-Gaedhil are often identified a body of plunderers, members of Meath and Cavan clans, who in the year 845 devastated large tracts of territory “after the manner of the Gentiles” (_Annals of Ulster_, A.D. 845). The Annalists call them “sons of death” (_maic báis_), possibly a term applied by the monastic chroniclers to a people who had abandoned their Christian baptism, and who had profaned churches and religious houses. (Cf. Marstrander, _op. cit._, p. 7, n.) [44] Cf. _Annals of the Four Masters_, A.D. 854. _Three Fragments of Annals_, A.D. 852, referring to the same event, mention the “fleet of the Gaill-Gaedhil.” [45] _Annals of Ulster_, A.D. 855. [46] _Annals of the Four Masters_, A.D. 856. [47] _Fragments of Annals_, A.D. 858.