The Isles of Scilly are an archipelago off the south western tip of the Cornish peninsula of Great Britain. It is the southernmost location in England and the United Kingdom, as well as the most westerly in England.
The population of all the islands at the 2011 census was 2,203. Scilly forms part of the ceremonial county of Cornwall, and some services are combined with those of Cornwall. However, since 1890, the islands have had a separate local authority. Since the passing of the Isles of Scilly Order 1930, this authority has had the status of a county council and today is known as the Council of the Isles of Scilly.
The adjective "Scillonian" is sometimes used for people or things related to the archipelago. The Duchy of Cornwall owns most of the freehold land on the islands. Tourism is a major part of the local economy, along with agriculture - particularly the production of cut flowers.
Scilly has been inhabited since the Stone Age, and until the early 20th century its history had been one of subsistence living. Farming and fishing continue, but the main industry now is tourism.
The islands may correspond to the Cassiterides (Tin Isles) visited by the Phoenicians and mentioned by the Greeks. However, the archipelago itself does not contain much tin - it may be that the islands were used as a staging post.
It is likely that until relatively recent times the islands were much larger and perhaps joined together into one island named Ennor. Rising sea levels flooded the central plain around 400–500 AD, forming the current 55 islands and islets, if an island is defined as "land surrounded by water at high tide and supporting land vegetation". The word Ennor is a contraction of the Old Cornish En Noer (Moer, mutated to Noer), meaning 'the land' or the 'great island'.
Evidence for the older large island includes:
- A description written during Roman times designates Scilly "Scillonia insula" in the singular, indicating either a single island or an island much bigger than any of the others.
- Remains of a prehistoric farm have been found on Nornour, which is now a small rocky skerry far too small for farming. There once was an Iron Age Britain community here that extended into Roman times. This community was likely formed by immigrants from Brittany, probably the Veneti who were active in the tin trade that originated in mining activity in Cornwall and Devon.
- At certain low tides the sea becomes shallow enough for people to walk between some of the islands. This is possibly one of the sources for stories of drowned lands, e.g. Lyonesse.
- Ancient field walls are visible below the high tide line off some of the islands (e.g. Samson).
- Some of the Cornish language place names also appear to reflect past shorelines, and former land areas.
- The whole of southern England has been steadily sinking in opposition to post-glacial rebound in Scotland: this has caused the rias (drowned river valleys) on the southern Cornish coast, e.g. River Fal and the Tamar Estuary.
Offshore, midway between Land's End and the Isles of Scilly, is the supposed location of the mythical lost land of Lyonesse, referred to in Arthurian literature, of which Tristan is said to have been a prince. This may be a folk memory of inundated lands, but this legend is also common among the Brythonic peoples; the legend of Ys is a parallel and cognate legend in Brittany as is that of Cantre'r Gwaelod in Wales.
Scilly has been identified as the place of exile of two heretical 4th century bishops, Instantius and Tiberianus, who were followers of Priscillian.
