Constitutional status of Cornwall of Exeter, styled himself as "King of the English, and ruler of this province of Britons". Edmund's successor Edgar styled himself "King of the English and ruler of the adjacent nations". This was followed by king Aethelred II (978–1016) describing Cornwall not as an English shire, but as a province, or client territory. Surviving charters issued by the Kings of England Edmund I (939–946), Edgar (959–975), Edward the Martyr (975–978), Aethelred II (978–1016), Edmund II (1016), Cnut (1016–1035) and Edward the Confessor (1042–1066) record grants of land in Cornwall made by these kings. In contrast to the easterly concentration of
Edward the Martyr the kingdom, ealdormen Ælfhere and Æthelwine, quarrelled, and civil war almost broke out. In the so-called anti-monastic reaction, the nobles took advantage of Edward's weakness to dispossess the Benedictine reformed monasteries of lands and other properties that King Edgar had granted to them. Edward's short reign was brought to an end by his murder at Corfe Castle in 978 in circumstances that are not altogether clear. His body was reburied with great ceremony at Shaftesbury Abbey early in 979. In 1001 Edward's remains were moved to a more prominent place in the abbey, probably with the blessing of his half-brother