Only Heathen Vikings

A story of Heathen Vikings enabling Cinaed (or Kenneth) MacAlpin take over Christian Scotland.
Cattan, warrior priest and Chief of the Clan Chattan, converted the ambitious, Kenneth of Dal Riada and became his personal advisor. Follow James who became the caretaker Chief, forming alliances against the greater threat of raiding Vikings, by a circumnavigation of mainland Britain noting changes of the time and developing tactics to fight back. The Chattan Fleet's reputation was such, that neither Dane nor Norse wished to take them on, so they went after soft targets, sometimes as paid mercenaries to regain lost lands.
Once Vikings settled in the northern isles, Man, and Dublin, they took possession of the east of Angleland that became England, and the west of Alba that became Scotland. Tribal identity became mixed as the kingdoms united but, the people still retained symbols of their ancient origins displayed on local banners, as they rallied to the nearest, strongest, High King's own standard.