"To the west, what is now Argyll, Kintyre, and the neighboring islands, lay the Kingdom of Dalriada. This area had been "colonized" in the 3rd and 4th centuries by the Scots, a warlike "Celtic" race from northern Ireland, who at first were overshadowed by the Picts, but were eventually to give their name to all of Scotland which, at the time, was known as Alba or Alban. The first written records of Scottish history are found in the works of Roman historian, Tacitus, whose father-in-law, Cnaeus Julius Agricola - the Governor of the Roman Province of Britain, invaded southern Scotland in 81 A.D. Agricola established his headquarters at Stirling. As he pushed northward with his army, he defeated the "native Caledonians" at Mons Graupius in eastern Scotland which some identify as the Hill of Moncreiffe. The Grampian mountains and the dense forest that covered much of central Scotland favored guerrilla warfare and the Caledonians took full advantage of them. If the Romans had not had their hands full elsewhere, they might have returned to try to conquer Scotland. But, by the end of the 4th century, the last remaining Roman outposts had been abandoned. So, Scotland only encountered the might of Rome occasionally and never became part of the Roman Empire or saw the benefits of an otherwise Roman civilization. But, by approximately 430 A.D., the Romans left Britain leaving the native Caledonians to their own devices and to the many of their more warlike and less civilized neighbors. Soon barbaric Teutonic invaders from across the North Sea, the Angles and Saxons, had taken over most of what is now England, driving the native Britons westwards into Wales and Cornwall and northwards into Cumbria and Strathclyde. Scotland was, at this time, divided between four different races: the Picts, Scots, Britons, and Anglo-Saxons.
The most powerful of these were the Picts, who were supreme from Caithness in the north to the Forth in the South. Of Celtic stock, they had, according to some authorities, originally arrived from the continent of Europe as part of the Celtic migrations that reached the British Isles at different times during the first millennium before Christ. Some say they were of Scythian origin. Although, the Picts and Scots occasionally combined forces to harass the Romans, the Scots who spoke a different language and where first loyalties were to their fellow Scots across the sea in Irish Dal Riata. The neighboring Britons of Strathclyde, another Celtic race, speaking a kindred tongue, controlled the area stretching from the Clyde to the Solway and beyond into Cumbria. To the east, the country south of the Forth was now occupied by the Teutonic Anglo-Saxons who held sway over an area stretching southwards into Northumbria. Like their Anglo-Saxon kinsmen further south, they came from the lands lying between the mouth of the Rhine and the Baltic. In 685, Pictish territory north of the Firth of Forth was invaded by a large Northumbrian army. An overwhelming Pictish victory permanently weakened Northumbrian power in Caledonia. About 730, Angus Mac Fergus, king of the Picts, subjugated Strathclyde and Dalriada. Relative peace followed until the late 8th century, when Vikings from Scandinavia began to raid the Caledonian coasts. Taking advantage of Pictish preoccupation with the invaders, the Scots and Britons soon regained their independence. In 844, Kenneth Mac Alpine, king of Dalriada, and later king of Scotland, who was a descendant of the Pictish royal family, obtained the crown of Pictland, probably with the assent of the harassed Picts. The united kingdoms, officially known as Alban, comprised all the territory north of the firths of Forth and Clyde. Kenneth and several of his successors vainly attempted to subdue the remaining Northumbrian possessions in Caledonia and, in alliance with Strathclyde, tried to halt the raids of the Vikings. Although, with the help of the Northumbrians, the Vikings were prevented from securing a foothold in Dalriada, but they seized various coastal areas in the north, east, and west, and occupied the Orkney and Shetland islands and the Hebrides. In later times, the rulers of England claimed the Scottish domain on the basis of the aid their forebears had given to Alban.
In the next three centuries after the departure of the Romans, the Picts, the Scots, the Britons, and the Angles were eventually converted to Christianity. Pagan traditions were deeply rooted. 'Places among the Britons, unpenetrated by the Romans, have come under the rule of Christ', wrote Tertullian in 208 A.D. However, in the 3rd century, St. Ninian's missionaries from Ireland, forged northward up the Great Glen toward Caithness and Sutherland, and even the Orkney and Shetland islands, and no doubt for linguistic reasons and partly for reasons of geography, had little contact with the Kingdom of Dalriada in the Western Isles.
Through the centuries, the first Scottish settlers in Dalriada, while consolidating their hold on the territories they had conquered, had remained in close touch with their parent kingdom in Ireland. Then, in about the year 500, Fergus Mac Erc and his two brothers, Angus and Lorne, led a fresh Scottish invasion from Ireland and established a new dynasty with its stronghold at Dunadd near Crinan, which now became the capital of Scottish Dalriada. But Fergus Mac Erc and his successors continued to pay tribute to Ireland and to accept Irish suzerainty, and it was from Ireland, that towards the middle of the 6th century the first Christian missionaries reached Dalriada. The earliest of these was St. Oran, who died of the plague in 548, after establishing Christian churches in Iona, Mull and Tiree, though not as yet on the mainland. Then in 563, St. Columba (Colum Cille in Ireland), arrived from Ireland, and having established himself on Iona, at once made it a base for his missions to the mainland and to the other islands. Columba was by any standards a remarkable man. Of royal birth and powerful intellect and physique, he seems to have left Ireland under some kind of cloud = (St. Columba, Colum Cille in Ireland, was accused of writing manuscripts illegally. His family, the Ui Neill dynasty, went to war on his behalf and won. But, because of the massive slaughter the war caused, Columba left and went to Iona). In Scottish Dalriada, his impact was to a high degree political as well as spiritual. Arriving on the scene at a moment when the Scots had suffered a crushing military defeat at the hands of the Picts, when their king had been killed, their morale was low and their very independence was threatened, he not only preached the Gospel, but at once took active measures to re-establish and consolidate the monarchy. Aiden the False, whom he now made king in place of the rightful heir to the throne, proved an astute and resourceful monarch. The good work which he began was carried on by his descendants, especially Eochaid the Venomous, who successfully infiltrated the enemy camp by marrying a Pictish princess. It was not long before the Scots were once again more than holding their own against the Picts. From Dalriada, Columba penetrated far into northern Pictland, quelling a monster which he encountered in Loch Ness and easily getting the best of the pagan priests he found at the court of the local king. By his death in 579, Dunadd had become an established political capital, while Iona was the nucleus of a fast-expanding church, organized, it may be observed, on lines that were not as yet Episcopal. From Ireland, too, came St. Moluag, who founded a monastery in 562 on the island of Lismore, and St. Maclrubba, who established himself at Applecross a century later. From the west, both traveled up and down Dalriada and far into Pictish territory, founding missions and monasteries as they went. Soon after St. Columba's death, St. Aidan had gone out from Iona to convert the Angles of Northumbria, establishing himself on Holy Island near Bamburgh, while St. Cuthbert, the apostle of the Anglo-Saxon Lothians, likewise drew his inspiration from the same source.
Though by the end of the 7th century, all four of the kingdoms of Alban (Scotland) had been converted to Christianity, they were still far from being united among themselves politically. Nor were they in unison theologically with the rest of Christendom. Out of touch with Rome, the Celtic clergy had developed views on such subjects as the style of the tonsure and the date of Easter which struck the Vatican and their fellow Christians further south as deplorable. 'Wicked, lewd, and wrongful', were some of the phrases used in this connection by no less an authority than the Venerable Bede. In the end, the Celts were to yield before superior wealth and organization. But they had made a notable contribution to the Christian heritage. 'The Celtic Church gave love', ran the saying, 'the Roman Church gave law'. It was the law that in the end prevailed.
Trouble, meanwhile, threatened from another quarter. From the end of the 8th century onwards, the Norsemen began their attacks on Scotland, gradually gaining a foothold, and then more than a foothold, on the islands and coastal areas. By the end of the 9th century, they had conquered Orkney, Shetland, and the Western Isles, and these were followed by Caithness and Sutherland. The divisions and disagreements of the four kingdoms weakened their resistance to the common enemy. Hostility still persisted between the Picts and Scots, while the Britons of Strathclyde would have no truck with the Angles of Lothian and Northumbria. For a time it had seemed possible that the Angles would achieve ascendancy over their neighbors, but the decisive defeat of their King Ecgfrith, by the Picts at the battle of Nectansmere, in 685 effectively ruled this out. It was not until the 9th century that some measure of unity was at last achieved. In the year 843, Kenneth Mac Alpine, King of the Scots of Dalriada and at the same time a claimant to the Pictish throne, a man we are told 'of marvelous astuteness' fell upon the Picts, to whose ruling dynasty he was related, after they had been weakened by the raids of the Norsemen, and having disposed of all rival claimants, made himself King of everything north of the Forth! From Dunadd, he moved his capital to Forteviot, in the heart of Pictish territory, while the religious center of his kingdom was shifted to Dunkeld. He now transferred St. Columba's remains from Iona. 'And so', says the Huntingdon chronicle, 'he was the first of the Scots to obtain the monarchy of the whole of Alban, which is now called Scotia' (Scotland).
Of the Picts, who had ruled over most of Scotland for more than a thousand years, little or nothing more was heard. They were, in the modern phrase, gleichgeschaltet, and so have gone down to history as a shadowy, ill-documented race of people of uncertain antecedents, possibly tattooed or "painted", for that is the Latin meaning of their name".
"Scotland", by Fitzroy Maclean, 1993 revised edition