Undoubtedly in these great families there was a good deal of what we call clannishness--of devotion to their particular interest to the detriment of the public or the national interest. On the other hand, it is quite a mistake to suppose that the hostility of clan to clan, as is often said, was the principal element of harm to peace. The Irish chronicles show clearly that domestic wars arose far more frequently from disputes and rivalries between members of a ruling family. It was the same among the Welsh, and a recent Welsh historian has justly traced this evil to the law of succession which was similar in the two countries--the choice of successor to king or lord being open between a number of claimants. A doubtful succession was the fruitful source of disorder in other countries also. Readers of history will remember its effects in the Roman empire, the wars of the Scottish succession before Bannockburn, the Wars of the Roses in England, the war of the Spanish succession. The feudal law of primogeniture tended to minimise this danger. Here we find another instance of the ignoring of time and change in books on Irish history. I think I am right in saying that most readers gather from these books the impression that the Irish institution of Tanistry dates from time immemorial. There is no mention of a tanist in the Annals until the thirteenth century, after feudal institutions had been established in many parts of Ireland; and we can trace the gradual spread of the custom in the fourteenth and fifteenth centuries. It seems right then to infer that those who lived under Irish law were impressed by the greater stability afforded by Feudal law in this matter of succession, perhaps also by the aggravation of their own plight owing to the opportunities that a disputed succession gave for the interference of the enemy in their midst; and that they sought to remove this evil and danger by determining the succession beforehand, choosing in the ruler's lifetime the man who was to succeed him, the tanist.