The Icelandic saga of Burnt Njal shows us in the most vivid possible way how great a shock Clontarf sent through the Norse world. The battle, it tells us, was accompanied or followed by apparitions and dreadful portents seen in the Hebrides, in the Orkneys, in the Faroe islands, and in distant Iceland. In truth a victory for Earl Sigurd might have been, as his defeat must have been, a decisive event in European history. The Norse of Dublin were comparatively not much affected. They maintained their alliance with Leinster. Three years after the battle, these confederates are again seen on the offensive, invading Bregia, and their joint forces sustain a heavy defeat from Mael Sechnaill. Though a close intercourse was maintained with Norsemen in other countries, the colonies of Dublin, Wexford, Waterford and Limerick became a domestic factor in the life of Ireland. Intermarriage with the Irish was quite common. We find Norse names in Irish families and Irish names in Norse families, and a considerable vocabulary of Norse words became at home in the Irish language. A new element, the commercial life of towns, was introduced by these colonies. X. MEDIEVAL IRISH INSTITUTIONS The Book of Rights divides Ireland into a little more than a hundred petty states (owing to certain peculiarities of treatment, the number cannot be stated definitely.) These are arranged in seven groups, with an over-king at the head of each group. The principal matter of the book is to define certain relations between the over-king of each group and the petty kings under him. All this is told in verse. The plan of the book is to allot two poems to each of the over-kingdoms or groups of states. One of the two poems relates the tributes payable by the petty states to the over-king at the head of the group. The other poem relates the customary gifts given by the over-king to the petty kings. Great importance was attached to this giving and receiving of gifts, and the significance of the gifts is clearly expressed in their Irish name, _tuarastal_. The meaning of this word, which is still in familiar use, is wages. The gifts then were not favours. The acceptance of them was an act of homage. The king who accepted _tuarastal_ from another king acknowledged himself to be that other king's man, to be, so to speak, in his pay--if only in a figurative or ceremonial sense.