Æscwine, or Erkenwine, Erchenwine, was reputedly the settler from Old Saxony who in 527 founded the Kingdom of Essex (in the area of modern-day England approximately covered by the county of that name), becoming the first king of the region (r. c. 527-587 ?).
Precious little evidence is available for his existence. His name Æscwine first appears in a West-Saxon genealogy which is imperfectly preserved in London, BL, Add. MS 23211, presumably of the late 9th century. Here he is said to be father to King Sledd and himself a son of Offa, son of Bedca, son of Sigefugl, son of Swæppa, son of Antsecg, son of Gesecg, son of Seaxnet (the legendary founder of the Saxons).
Further information is supplied by works of historians writing in the 12th and 13th centuries, who appear to have used pre-Conquest material, i.e. Henry of Huntingdon's Historia Anglorum, Roger of Wendover's Flores Historiarum and Matthew Paris's Chronica Majora. These, however, substitute the name Æscwine for Erkenwine or Erchenwine as Sledd's father. Both these names seem to betray Kentish connections.