Picts in the context of "Language shift"

The Celts (/kɛlts/ KELTS, see pronunciation for different usages) or Celtic peoples (/ˈkɛltɪk/ KEL-tik) were a collection of Indo-European peoples in Europe and Anatolia, identified by their use of Celtic languages and other cultural similarities. Major Celtic groups included the Gauls; the Celtiberians and Gallaeci of Iberia; the Britons, Picts, and Gaels of Britain and Ireland; the Boii; and the Galatians. The interrelationships of ethnicity, language and culture in the Celtic world are unclear and debated; for example over the ways in which the Iron Age people of Britain and Ireland should be called Celts. In current scholarship, 'Celt' primarily refers to 'speakers of Celtic languages' rather than to a single ethnic group.

The history of pre-Celtic Europe and Celtic origins is debated. The traditional "Celtic from the East" theory, says the proto-Celtic language arose in the late Bronze Age Urnfield culture of central Europe, named after grave sites in southern Germany, which flourished from around 1200 BC. This theory links the Celts with the Iron Age Hallstatt culture which followed it (c. 1200–500 BC), named for the rich grave finds in Hallstatt, Austria, and with the following La Tène culture (c. 450 BC onward), named after the La Tène site in Switzerland. It proposes that Celtic culture spread westward and southward from these areas by diffusion or migration. A newer theory, "Celtic from the West", suggests proto-Celtic arose earlier, was a lingua franca in the Atlantic Bronze Age coastal zone, and spread eastward. Another newer theory, "Celtic from the Centre", suggests proto-Celtic arose between these two zones, in Bronze Age Gaul, then spread in various directions. After the Celtic settlement of Southeast Europe in the 3rd century BC, Celtic culture reached as far east as central Anatolia, Turkey.

The Britons (*Pritanī, Latin: Britanni, Welsh: Brythoniaid), also known as Celtic Britons or ancient Britons, were the Celtic people who inhabited Great Britain from at least the British Iron Age until the High Middle Ages, at which point they diverged into the Welsh, Cornish, and Bretons (among others). They spoke Common Brittonic, the ancestor of the modern Brittonic languages.

The earliest written evidence for the Britons is from Greco-Roman writers and dates to the Iron Age. Ancient Britain was made up of many tribes and kingdoms, associated with various hillforts. The Britons followed an ancient Celtic religion overseen by druids. Some of the southern tribes had strong links with mainland Europe, especially Gaul and Belgica, and minted their own coins. The Roman Empire conquered most of Britain in the 1st century AD, creating the province of Britannia. The Romans invaded northern Britain, but the Britonnic tribes such as the Caledonians and Picts in the north remained unconquered, and Hadrian's Wall which bisects modern Northumbria and Cumbria became the edge of the empire. A Romano-British culture emerged, mainly in the southeast, and British Latin coexisted with Brittonic. It is unclear what relationship the Britons had with the Picts, who lived outside of the empire in northern Britain; however, most scholars today accept the fact that the Pictish language was closely related to Common Brittonic.

Scottish people or Scots (Scots: Scots fowk; Scottish Gaelic: Albannaich) are an ethnic group and nation native to Scotland. Historically, they emerged in the early Middle Ages from an amalgamation of two Celtic peoples, the Picts and Gaels, who founded the Kingdom of Scotland (or Alba) in the 9th century. In the following two centuries, Celtic-speaking Cumbrians of Strathclyde and Germanic-speaking Angles of Northumbria became part of Scotland. In the High Middle Ages, during the 12th-century Davidian Revolution, small numbers of Norman nobles migrated to the Lowlands. In the 13th century, the Norse-Gaels of the Western Isles became part of Scotland, followed by the Norse of the Northern Isles in the 15th century.

In modern usage, "Scottish people" or "Scots" refers to anyone whose linguistic, cultural, family ancestral or genetic origins are from Scotland. The Latin word Scoti originally referred to the Gaels, but came to describe all inhabitants of Scotland. Considered pejorative by some, the term Scotch has also been used for Scottish people, now primarily outwith Scotland.

Flavius Valerius Constantius (c. 250 – 25 July 306), also called Constantius I, was a Roman emperor from 305 to 306. He was one of the four original members of the Tetrarchy established by Diocletian, first serving as caesar from 293 to 305 and then ruling as augustus until his death. Constantius was also father of Constantine the Great, the first Christian emperor of Rome. The nickname "Chlorus" (Ancient Greek: Χλωρός, lit. 'the Pale') was first popularized by Byzantine-era historians and not used during the emperor's lifetime.

As an Illyrian soldier of humble origin, Constantius had a distinguished military career and rose to the top ranks of the army. Around 289, he set aside Helena, Constantine's mother, to marry a daughter of Emperor Maximian, and in 293 was added to the imperial college by Maximian's colleague Diocletian. Assigned to rule Gaul, Constantius defeated the usurper Carausius there and his successor Allectus in Britain, and campaigned extensively along the Rhine frontier, defeating the Alamanni and Franks. When the Diocletianic Persecution was announced in 303, Constantius ordered the demolition of churches but did not actively hunt down Christians in his domain. Upon becoming senior emperor in May 305, Constantius launched a successful punitive campaign against the Picts beyond the Antonine Wall. He died suddenly at Eboracum (York) in July the following year.

The Anglo-Scottish border is a boundary in Great Britain that separates England and Scotland. It runs for 96 miles (154 km) between Marshall Meadows Bay on the east coast and the Solway Firth in the west.

The Firth of Forth was the border between the Picto-Gaelic Kingdom of Alba and the Anglian Kingdom of Northumbria in the early 10th century. It became the first Anglo-Scottish border with the annexation of Northumbria by Anglo-Saxon England in the mid-10th century. In 973, the Scottish king Kenneth II attended the English king Edgar the Peaceful at Edgar's council in Chester. After Kenneth had reportedly done homage, Edgar rewarded Kenneth by granting him Lothian. Despite this transaction, the control of Lothian was not finally settled and the region was taken by the Scots at the Battle of Carham in 1018 and the River Tweed became the de facto Anglo-Scottish border. The Solway–Tweed line was legally established in 1237 by the Treaty of York between England and Scotland. It remains the border today, with the exception of the Debatable Lands, north of Carlisle, and a small area around Berwick-upon-Tweed, which was taken by England in 1482. Berwick was not fully annexed into England until 1746, by the Wales and Berwick Act 1746.

The barbarian invasions of the third century (212–305) constituted an uninterrupted period of raids within the borders of the Roman Empire, conducted for purposes of plunder and booty by armed peoples belonging to populations gravitating along the northern frontiers: Picts, Caledonians, and Saxons in Britain; the Germanic tribes of Frisii, Saxons, Franks, Alemanni, Burgundians, Marcomanni, Quadi, Lugii, Vandals, Juthungi, Gepids and Goths (Tervingi in the west and Greuthungi in the east), the Dacian tribes of the Carpi and the Sarmatian tribes of Iazyges, Roxolani and Alans, as well as Bastarnae, Scythians, Borani and Heruli along the Rhine-Danube rivers and the Black Sea.

Since the time of Marcus Aurelius during the Marcomannic Wars (166/167-189), Germanic-Sarmatian tribes had not exerted such strong pressure along the northern borders of the Roman Empire.

The Inner Hebrides (/ˈhɛbrɪdiːz/ HEB-rid-eez; Scottish Gaelic: na h-Eileanan a-staigh, lit. 'the Inner Isles') is an archipelago off the west coast of mainland Scotland, to the south east of the Outer Hebrides. Together these two island chains form the Hebrides, which experience a mild oceanic climate. The Inner Hebrides comprise 35 inhabited islands as well as 44 uninhabited islands with an area greater than 30 hectares (74 acres). Skye, Mull, and Islay are the three largest, and also have the highest populations. The main commercial activities are tourism, crofting, fishing and whisky distilling. In modern times the Inner Hebrides have formed part of two separate local government jurisdictions, one to the north and the other to the south. Together, the islands have an area of about 4,130 km (1,594 sq mi), and had a population of 18,948 in 2011. The population density is therefore about 4.6 inhabitants per square kilometre (12 inhabitants per square mile).

There are various important prehistoric structures, many of which pre-date the first written references to the islands by Roman and Greek authors. In the historic period the earliest known settlers were Picts to the north and Gaels in the southern kingdom of Dál Riada prior to the islands becoming part of the Suðreyjar kingdom of the Norse, who ruled for over 400 years until sovereignty was transferred to Scotland by the Treaty of Perth in 1266. Control of the islands was then held by various clan chiefs, principally the MacLeans, MacLeods and MacDonalds. The Highland Clearances of the 19th century had a devastating effect on many communities and it is only in recent years that population levels have ceased to decline.