Insular Celts in the context of "Celtic currency of Britain"

The Gaels (/ɡeɪlz/ GAYLZ; Irish: Na Gaeil [n̪ˠə ˈɡeːlʲ]; Scottish Gaelic: Na Gàidheil [nə ˈkɛː.al]; Manx: Ny Gaeil [nə ˈɡeːl]) are an Insular Celtic ethnic group native to Ireland, Scotland, and the Isle of Man, and historically, Iceland and the Faroe Islands. They are associated with the Gaelic languages: a branch of the Celtic languages comprising Irish, Manx, and Scottish Gaelic.

Gaelic language and culture originated in Ireland, extending to Dál Riata in western Scotland. In antiquity, the Gaels traded with the Roman Empire and also raided Roman Britain. In the Middle Ages, Gaelic culture became dominant throughout the rest of Scotland and the Isle of Man. There was also some Gaelic settlement in Wales, as well as cultural influence through Celtic Christianity. In the Viking Age, small numbers of Vikings raided and settled in Gaelic lands, becoming the Norse-Gaels. In the 9th century, Dál Riata and Pictland merged to form the Gaelic Kingdom of Alba (Scotland). Meanwhile, Gaelic Ireland was made up of several kingdoms, with a High King often claiming lordship over them.

Roman Britain was the territory that became the Roman province of Britannia after the Roman conquest of Britain, consisting of a large part of the island of Great Britain. The occupation lasted from AD 43 to AD 410.

Britain was invaded by Julius Caesar in 55 and 54 BC as part of the Gallic Wars. According to Caesar, the Britons had been overrun or culturally assimilated by the Belgae during the British Iron Age and had been aiding Caesar's enemies. The Belgae were the only Celtic tribe to cross the sea into Britain, for to all other Celtic tribes this land was unknown. He received tribute, installed the Celtic king Mandubracius over the Trinovantes, and returned to Gaul. Planned invasions under Augustus were called off in 34, 27, and 25 BC. In 40 AD, Caligula assembled 200,000 men at the Channel on the continent, only to have them gather seashells (musculi) according to Suetonius, perhaps as a symbolic gesture to proclaim Caligula's victory over the sea. Three years later, Claudius directed four legions to invade Britain and restore the exiled king Verica over the Atrebates. The Romans defeated the Catuvellauni, and then organized their conquests as the province of Britain. By 47 AD, the Romans held the lands southeast of the Fosse Way. Control over Wales was delayed by reverses and the effects of Boudica's uprising, but the Romans expanded steadily northwards.

Celtic mythology is the body of myths belonging to the Celtic peoples. Like other Iron Age Europeans, Celtic peoples followed a polytheistic religion, having many gods and goddesses. The mythologies of continental Celtic peoples, such as the Gauls and Celtiberians, did not survive their conquest by the Roman Empire, the loss of their Celtic languages and their subsequent conversion to Christianity. Only remnants are found in Greco-Roman sources and archaeology. Most surviving Celtic mythology belongs to the Insular Celtic peoples (the Gaels of Ireland and Scotland; the Celtic Britons of western Britain and Brittany). They preserved some of their myths in oral lore, which were eventually written down by Christian scribes in the Middle Ages. Irish mythology has the largest written body of myths, followed by Welsh mythology.

The supernatural race called the Tuatha Dé Danann is believed to be based on the main Celtic gods of Ireland, while many Welsh characters belong either to the Plant Dôn ("Children of Dôn") or the Plant Llŷr ("Children of Llŷr"). Some figures in Insular Celtic myth have ancient continental parallels: Irish Lugh and Welsh Lleu are cognate with Lugus, Goibniu and Gofannon with Gobannos, Macán and Mabon with Maponos, and so on. One common figure is the sovereignty goddess, who represents the land and bestows sovereignty on a king by marrying him. The Otherworld is also a common motif, a parallel realm of the supernatural races, which is visited by some mythical heroes. Celtic myth influenced later Arthurian legend.

The Caledonians (/ˌkælɪˈdoʊniənz/; Latin: Caledones or Caledonii; Ancient Greek: Καληδῶνες, Kalēdōnes) or the Caledonian Confederacy are believed to be a Brittonic-speaking (Celtic) tribal confederacy in what is now Scotland during the Iron Age and Roman eras. The Greek form of the tribal name gave rise to the name Caledonia for their territory. The Caledonians were considered to be a group of Britons, but later, after the Roman conquest of the southern half of Britain, the northern inhabitants were distinguished as Picts, thought to be a related people who would have also spoken a Brittonic language. The Caledonian Britons were thus enemies of the Roman Empire, which was the state then administering most of Great Britain as the Roman province of Britannia.

The Caledonians, like many Celtic tribes in Britain, were hillfort builders and farmers who defeated and were defeated by the Romans on several occasions. The Romans never fully occupied Caledonia, though several attempts were made. Nearly all of the information available about the Caledonians is based on predominantly Roman sources, which may be biased.

Lugus (sometimes Lugos or Lug) is a Celtic god whose worship is attested in the epigraphic record. No depictions of the god are known. Lugus perhaps also appears in Roman sources and medieval Insular mythology.

Various dedications, concentrated in Iberia and dated to between the 1st century BCE and the 3rd century CE, attest to the worship of the god Lugus. However, these predominately describe the god in the plural, as the Lugoves. The nature of these deities, and their relationship to Lugus, has been much debated. Only one, early inscription from Peñalba de Villastar, Spain is widely agreed to attest to Lugus as a singular entity. The god Lugus has also been cited in the etymologies of several Celtic personal and place-names incorporating the element "Lug(u)-" (for example, that of the prominent Roman settlement Lugdunum).