Roman invasions and occupations of southern Scotland were a series of brief interludes.
According to the Roman historian Tacitus, the Caledonians "turned to armed resistance on a large scale", attacking Roman forts and skirmishing with their legions.
Tacitus wrote that, before the battle, the Caledonian leader, Calgacus, gave a rousing speech in which he called his people the "last of the free" and accused the Romans of "making the world a desert and calling it peace" (freely translated).
After the Roman victory, Roman forts were briefly set along the Gask Ridge close to the Highland line (only Cawdor near Inverness is known to have been constructed beyond that line).
The well-preserved village of Skara Brae on the mainland of Orkney dates from this period.
The Kingdom of the Picts as it was in the early 8th century, when Bede was writing, was largely the same as the kingdom of the Scots in the reign of Alexander I (1107–1124).
However, by the tenth century, the Pictish kingdom was dominated by what we can recognise as Gaelic culture, and had developed a traditional story of an Irish conquest around the ancestor of the contemporary royal dynasty, Cináed mac Ailpín (Kenneth Mac Alpin).
Repeated glaciations, which covered the entire land mass of modern Scotland, destroyed any traces of human habitation that may have existed before the Mesolithic period.
It is believed the first post-glacial groups of hunter-gatherers arrived in Scotland around 12,800 years ago, as the ice sheet retreated after the last glaciation.