26 The Round Towers. 



constantly visited and plundered by them. The two nations of 

 Northmen are represented as hostile to each other, and battles 

 between them took place frequently in Irish waters or on the 

 mainland. But these feuds did not interfere with their main 

 object, which was the persistent plundering of the country, and 

 the carrying away as slaves of thousands of men, women, and 

 children. We find that Armagh was plundered by the Danes 

 in seventeen different years from a.d. 833 to 1016, and it was 

 attacked three times in one month. The church of Maghera 

 was attacked three times in one month. Clonard, the seat of 

 one of the great schools in Ireland, was invaded seven times 

 from 838 to 1020. Before the year 900 the Norsemen had first 

 ravaged the coast and the outlying islands, and then their boats 

 were repeatedly seen on the Boyne, the Liffey, and the Shan- 

 non. In the valleys of these rivers distinct groups of these 

 towers and churches are to be seen that had been for the first 

 seventy years of this war attacked and desecrated with such 

 fury. After reviewing some historical records as to the build- 

 ing of certain towers and peculiarities in their construction, 

 Miss Stokes writes : — " Thus we find three distinct periods to 

 which these towers may be assigned — first, from a.d. 890 to 

 927 ; secondly, from 973 to 1013 ; thirdly, from 1178 to 1238 ; 

 and of these three periods the first two were marked by a cessa- 

 tion of hostilities with the Northmen, while the Irish made 

 energetic efforts to repair the mischief caused by the invasions 

 of the heathen. It is clear that these three divisions are dis- 

 tinctly marked by three steps in the progressive ascent of 

 architecture, from the primitive form of the entablature to that 

 of the decorated Romanesque arch. The churches built by 

 Cormac O'Killen are characterised by the horizontal lintel ; the 

 church of King Brian, at Iniscaltra, with its still partially 

 developed Romanesque doorway and chancel arch, while re- 

 taining the rude form in its minor apertures, marks a period of 

 transition from the horizontal to the round arched style ; and 

 the buildings of Queen Dervorgilla and Turlough O'Connor, 

 with the doorway of Clonfert, show what the latter style 

 became in the lifetime of Donough O'Carroll. If Lusk, Glen- 



