One of the most decorative maps of the county, in fine original colour.

The map appears in John Speed's 'Theatre and Empire of Great Britaine'. The 'Theatre' followed the model of Ortelius's 'Theatrum orbis terrarum' - first published in English in 1606 - in its title and its format, with map-sheets backed by historical and geographical texts and gazetteers of place names. It was the earliest English attempt at producing an atlas on a grand scale, with the first detailed maps of the provinces of Ireland, the first set of county maps consistently attempting to show the boundaries of territorial divisions, and the first truly comprehensive set of English town plans-a notable contribution to British topography. Perhaps as many as fifty of the seventy-three towns had not previously been mapped, and about fifty-one of the plans were probably Speed's own work.

His map of Cornwall is based on the work of John Norden's map of the county. John Norden (1548-1625) had himself planned a county atlas of England and Wales. However, he only managed to survey eight of the fifty-two counties before he ran into financial trouble

John Speed is perhaps the most famous single figure in the early history of the English map trade. He was a member of the Merchant Taylors' Company, made free in September 1580, and later Fellow of the Society of Antiquaries. By training he was probably a rolling-press printer, but by interest he was a historian, and Queen Elizabeth granted him a sinecure in the Customs House, to give him the opportunity to pursue these interests. His earliest cartographic publications were historical; in 1595, he published a wall map of the Holy Land, Canaan as it was Possessed both in Abraham and Israels Dayes, a two-sheet map of The Invasions of England and Ireland with all their Civill Warres since the Conquest (1601) and a wall map of England, Wales and Ireland showing the same information, [1603-1604]. In 1611 he prepared two Bible maps, the larger inserted in folio editions of the great King James Bible, the smaller in octavo printings; Speed also secured a privilege, dated 31st October 1610, to ensure that the map was inserted in every copy of the Bible sold, a lucrative arrangement that the Stationers' Company eventually felt impelled to buy out from his heirs. Speed always considered his History of Great Britaine (1611) his major work, but his reputation was established by the companion atlas volume, Theatre of the Empire of great Britaine, published in 1612, the first printed atlas of the British Isles. The earliest map prepared was The County Palatine of Chester [1604], but the death of the engraver William Rogers meant that Speed's publishers had to turn to Jodocus Hondius, an Amsterdam engraver, to prepare the maps. The atlas was completed in 1612; the maps are notable for the decorative elements included, evidence of Speed's interest in antiquities and most have inset town-plans, the first series of printed town-plans of the British Isles, and were issued with descriptive English text printed on the verso. In the hands of different publishers, there were numerous editions to 1676 with text; later printings into the 1770s were issued without text. Towards the end of his career, Speed also prepared a world atlas: the Prospect of the most Famous Parts of the World (1627), the first world atlas compiled by an Englishman and published in England, although the maps were engraved in Amsterdam, using Dutch models. Again, this was printed with English text on the verso, and reprinted thereafter. While early editions are rarer, perhaps the most important edition was the 1676 printing, which added newly prepared English maps of New England, Virginia, the Carolinas, Barbados and Jamaica. Speed's publishers also prepared two pocket atlases, colloquially called "miniature Speeds", reproducing the Theatre and Prospect on a smaller, less expensive, format. The county atlas, England, Wales, and Ireland: … their several Counties abridged, first appeared in 1627, although there is an earlier proof version from about 1620; the A Prospect of the Most Famous Parts of the World appeared in 1646; both were reprinted in several editions up to 1675. However, Speed himself probably had little creative contribution to either atlas.