Cheshire, settled by Anglo-Saxons in the later seventh century, has many placenames of British origin, as well as Irish place-names given by tenth-century migrants from Ireland. Twenty-seven real or supposed instances are discussed here: Arclid, Antrobus, Arrow, Bollin, Brynn, Cilgwri, Crewe, Dane, Dee, Eccleston, Goyt, Ince, Landican, Liscard, Lostock, Lyme, Mellor, Mottram, Noctorum, Peover, Rhedynfre, Tarvin, Tintwistle, Tybrunawt/Tybrunawg, Weaver, Werneth, Wheelock. Ten of them are provided with derivations at variance with The Cambridge Dictionary of English Place-Names and other handbooks. Also discussed are three Welsh forms (Cilgwri, Rhedynfre, Tybrunawt/Tybrunawg) sometimes related to Cheshire. Although the second is certainly Farndon in the county’s south-west, the first and third have no Cheshire link. Cilgwri may be identified as a place near Corwen, Denbighshire. Tybrunawt/Tybrunawg or ‘Brunian House, House on (the River) Browney’, a book-name for the location of the Battle of Brunanburh in 937, should be identified with the Roman fortress of Lanchester above the River Brune or Browney, Co. Durham. Hence Brunanburh means ‘fortress of the Browney’. Other historical information is provided by Arclid, apparently the Arecluta where the British-Latin writer Gildas was born in 493. Analysis of toponyms thus provides new data on Cheshire’s past, while refuting earlier theories.