Pterist and I have been having an offline conversation about this topic. See book. If interested in joining the discussion please feel free to respond.
Celts and Romans
The Iron age took place in Scotland around 700BC and the native population traded and adopted new technologies. The celtic knotwork and decoration which is still admired today began in this period and the celts loved to decorate metal work and wore colourful clothes and jewellery. The Romans called the tribes of the north 'Caledoni' and named their land Caledonia.
The tribes in Caledonia resisted Roman invasion and the Romans tried a number of tactics to keep the peace in the north. They built two walls: the Antonine Wall which stretched from the Forth to the Clyde and Hadrian's Wall, both massive undertakings and designed to keep the fierce tribes of Caledonia out of Roman Britain.
http://archive.org/details/historyofancient00macluoft
The Masonic Legend of The Hebrew Prophet and Irish Prince (fun read as fantasy-fiction)