In 1870-72, John Marius Wilson's Imperial Gazetteer of England and Wales described Tresco like this:
TRESCOE, one of the Scilly Islands; 2 miles NW of St. Mary's. It is next in size to St. Mary's; contains a village, called Dolphin; contains also the residence of the proprietor of the islands, on the site of an abbey, founded in the 10th century, and annexed in the time of Henry I. to Tavistock abbey; contains likewise ruins of two fortalices, called Charles' Castle and Oliver Cromwell's Castle: has, at its NE point, a cavern at least 600 feet long, called Piper's Hole; ranks as a chapelry united with Bryher, and annexed to St. Mary's; and retains walls and arches of the ancient abbey church. Pop., 399. Houses, 91.
A Vision of Britain through Time includes a large library of local statistics for administrative units. For the best overall sense of how the area containing Tresco has changed, please see our redistricted information for the modern district of Isles of Scilly. More detailed statistical data are available under Units and statistics, which includes both administrative units covering Tresco and units named after it.
GB Historical GIS / University of Portsmouth, History of Tresco, in Isles of Scilly and Cornwall | Map and description, A Vision of Britain through Time.
Date accessed: 08th July 2015
Click here for more detailed advice on finding places within A Vision of Britain through Time, and maybe some references to other places called "Tresco".