Scotland's recorded history began with the arrival of the Roman Empire in the 1st century, when the province of Britannia reached as far north as the line between the firths of Clyde to the Forth.North of this was Caledonia, whose people were known in Latin as "Picti", "the painted ones".
Agricola's successors were unable or unwilling to further subdue the far north.
The Kingdom of Scotland was united under the descendants of Kenneth Mac Alpin, first king of a united Scotland.
His descendants, known to modern historians as the House of Alpin, fought among each other during frequent disputed successions.
Constant uprisings forced Rome's legions back: Hadrian's Wall attempted to seal off the Roman south and the Antonine Wall attempted to move the Roman border north.
The latter was swiftly abandoned and the former overrun, most spectacularly during the Great Conspiracy of the 360s.