The people who live in what is now Scotland before the Romans invaded were known as Picts. They stayed all across the highlands. Several different Celtic* tribes lived in the Lowlands and Borders. During the time of Roman occupation, the Picts made alliances with Irish tribes to help fight against the Romans. Irish raiders attacked the West coast of Britannia during this time. In response, the Romans strengthened their coastal defences by building forts and signal stations and by basing a fleet in the Bristol Channel. Meanwhile in Ireland there had been an improvement in farming methods. 'Improved farming would have led to increased food supply, and this may be linked with possible evidence for a considerable population explosion in Ireland from AD300 onwards.' (Laing, p32)
        With more people in the country, good fertile land became scarce, so they began to look for other places to settle. Due to the strength of the Roman border, the Irish settlers looked to lands beyond the control of the Roman Empire. They found a largely uninhabited part of Pictland that is now Argyll and Bute. The settlers came from an area of Ireland called Dalriada (modern County Antrim) and that is the name that they gave to their new territory. These settlers were called Scots, the word "Scot" being the Irish for "Bandit", though it is believed that neither the Romans or the Britons called them it.
        In the AD600's and 700's the Scots and the Picts were hostile to each other at various times. In the late AD730's the Pictish King Oengus the 1st began a take over of Dalriada, capturing Dunadd in AD736 while his brother Talorcan defeated a Daltiadan army a few miles away at Loch Awe. ' Yet even if Oengus won by conquest the overlordship of Dalriada in AD741, by AD750 he is said in the Annals of Ulster to have lost it, perhaps because of the intervention of Teudubr, King of Strathclyde.' (Lynch, p22)
        The Scots and Picts were similar  races of people, both being Celtic. The Scots were an agricultural people, that is, they were mostly farmers, but were also sailors. In fact, each family group (or clan) was expected to provide sailors in times of was. 'Each one of the twenty houses of Dalriada had to provide twenty eight oarsmen, that is, the crew for two seven-bench ships.' (Laing, p58). The Scots traded with Ireland, Pictland and even the Romans, and later the Anglo-Saxons who took over South Britain after the Romans left. Archaologists have found artefacts such as items of clothing and jewellry from these lands in Scots' sites. There is also evidence of trade with Europe. probably begun during Roman times, along established trade routes.
    Outside of their four Citadels, the people of Dalriada lived in small hamlets and farmsteads. Land owners or local Lords lived in Duns - farms fortified by a pallisade and circular ditch, like the Raths found in Ireland. Both the words Dun and Rath can still be found, in various forms, in modern place names in Scotland. Another type of house found in this region, and in the Lowlands, is the Crannog. A Crannog is a large, round wooden house built on stilts off the shores of Lochs. There is even evidence for Crannogs in the Firth of Clyde near Langbank, where until the 19th Century the river was quite shallow (it was artificially deepened to allow bigger ships to reach glasgow).
        Eventually the two Kingdoms - Dalriada and Pictland, were united under one King, Kenneth Mac Alpin, sometime between AD839 and AD844, creating the Kingdom of Alba, sometimes referred to as the Kingdom of the Scots


*The words Celt, Celtic and Celts are pronounced with a hard C with a K sound, as in the word  'cut', not a soft C with an 'sss' sound