The fatality attending the northern districts never seems to have extended to the junior branch of the reigning dynasty, whose alliances and expeditions were essentially connected with the south and west. It was over Strath Clyde that Constantine endeavoured to extend his influence; Northumbria was the province from which Indulf wrested Edinburgh; whilst Lothian, or the British frontiers, were fatal to Colin and his brother Eocha. Hence it may be gathered that they were the southern branch of the ruling family, the possessions of the kindred race of Constantine the First probably bringing the latter into more immediate contact with the northern division of the nation. Upon the extinction of the line of Aodh in the person of Constantine the Third, Malcolm the Second appears as the leader of the southern interest, and whilst the children of Kenneth MacDuff eventually became connected with the hereditary enemies of their race, Malcolm, in pursuance of the traditional policy of the south, allied himself with the House of Atholl, annexed Strath Clyde to the crown, and followed up the conquests of Indulf, and the attempts of his own father, Kenneth, upon the neighbouring possessions of the Northumbrian Ealdormen. The preponderance of the south was greatly increased during his reign, and as the conquests of Angus and his successors centred the royal authority in one ruling family, so the great additions made to the territory of the crown during the reign of Kenneth and his son Malcolm fixed that authority in the House of Atholl. The northern policy of these kings was reversed by their descendant Duncan, the result costing him his crown and his life; but a period was now approaching when the lengthened reign of an abler prince was to redeem the incapacity or misfortunes of the first of his House, to extend the power of the crown still further over the hostile provinces of the north, and to bequeath to his descendants a more compact and powerful kingdom, which they were destined gradually to knit together in the iron bonds of feudalism.