In order to understand the history of Scotland, one must first understand the geography of the land. Scotland is separated by the Forth, which may be crossed at first at Stirling, which lies along a narrow isthmus of land that was marked by boggy marshland until the 18th century. Here marks the separation of the land and is known as the Highlands north of the Forth and the Lowlands south of the Forth.

During the time of Ptolemy, Scotland was inhabited in the Highlands by ten tribes: the Venicanes in Fife, the Carnovii in Caithness, the Creones between Loch Linnhe and Loch Carron. There were vast differences between the tribes north and south of the Forth/ Clyde line. In the south, seven tribes controlled more consolidated territorial or tribal tracts, while the ten northern tribes lived along the coastline in the north wielding power into the heart of the Highlands. In Galloway were the Novantae who were separated from the Damnonii in Clydesdale by the Carrick Hills. Controlling most of Lothian and Berwickshire and Northumberland were the Vatadini. In the south, the land was separated by natural features that ran north and south. The territory of the Vatadini was divided from the Selgavae in Liddesdale and Teviotdale with their control ending at the valley of Nith that marked the territory of the Navantae.

Even the Romans were unable to penetrate the Highlands of Scotland. This land was known by Tacitus as Caledonia. This land was again attempted by Emperor Septimus Severus in AD 209, who with a force of 40,000 men was unable to conquer the land of the Highland Scots: Caledonia. In AD 297 the first mention of Picts was made when they, along with the Scoti, or Irish, attacked Roman forces along the frontier.

References from the second half of the fourth century imply a division of the Picts into two groups: the Dicalydanes in Strathearn and Monteith and the Verturianes, divided by the Mounth.

The geography of the Highlands encouraged the development of a large number of separate tribes. History points to a great amount of migration and contact by sea. Due to the nature of the geography, the development of a strong authority was difficult.

The Scots are descended from the ancient Celts and are therefore marked with the Celtic gifts of orators and artists as well as noble warriors.

The Dal Riada (Scots from Ireland), a celtic group, arrived in Scotland before 500 AD and may have occurred long before this time.. It is believed that this group went to Scotland during a period of decline, such as a famine that began around the first century BC. This disaster seems to have ended by the second century AD and by 300 AD the society seems to have recovered, which may have led to a population explosion. Western Scotland, with whom the Scoti probably had a trading relationship, would have been an inviting prospect. In the 6th century, Gildas mentions the Irish in the northwest of Britain as joining the Picts in attacking the Romans. By the 8th century, Bede also included the Scots as residents of northwestern Britain. Even as early as 400 AD the Roman Claudian Claudianus mentions the Scot in the "remoter Britons".

Ptolemy's map of tribes of Scotland include the Brigantes, Parisii and Cassii, all European Celtic tribes. The Brigantes originated in Switzerland and Upper Bavaria; the Parisii from the area now known as Paris and the Cassi from the same group as the Veliocasses, Baliocasses etc. Some of the tribes included in Ptolemy's map arrived in Britain during or shortly following Caesar's invasion of Gaul such as the Parisii and Belgae and Attrebates.At the time of Tacitus the Caledonii were strong enough north of the Clyde to have the land named after them, Caledonia. Tacitus mentions a tribe, the Boresti, unmentioned in Ptolemy's map and perhaps absorbed into other tribes.

Using the legend of Cairbre Riata a date of Cairbre's emigration to Scotland may be placed at roughly 125 AD. It is possible that the Eoghanacht were the original founders of the Scots colony of Northern Britain. Cairbre Riata is said to have come from Munster and the Eoganacht dynasty who ruled Munster in the 5th and 6th century are said to have originated in Scotland.

Around 330 BC the first of the Scots to arrive in mainland Britain was Fergus, King of Ireland, son of Feradach. It is said that the Scots and the Picts had long been allies.

Robert Louis Stevenson