Kentish is one of the four major dialect groups of Old English, spoken in the Anglo-Saxon kingdom of Kent and parts of Surrey and Sussex. It continued as a recognizable Middle English dialect through the fourteenth century. Kentish is the least well-attested of the Old English dialects, with a relatively small surviving corpus compared to West Saxon or Mercian.
The Kentish dialect had distinctive phonological features. Old English front rounded vowels (y, ȳ) were unrounded to (e, ē) earlier in Kentish than in other dialects. Kentish also showed some distinctive spellings reflecting its sound system, including e for West Saxon y (e.g., Kentish ber(e)g vs. West Saxon byrg for “city”) and specific developments of diphthongs.
The dialect’s historical importance lies partly in its geographical position: Kent was the first Anglo-Saxon kingdom to be Christianized (Augustine of Canterbury, 597 CE), and some of the earliest Old English glosses and charters come from Kent. The Kentish dialect’s subsequent evolution contributed to the formation of London English and, through it, to the standard language — London sat at the intersection of Kentish, Mercian, and East Saxon dialect areas.