Edward the Martyr was King of England from 975 until he was murdered in 978. Edward was the eldest son of King Edgar the Peaceful but was not his father's acknowledged heir. On Edgar's death, the leadership of England was contested, with some supporting Edward's claim to be king and others supporting his younger half-brother Æthelred the Unready, recognized as a legitimate son of Edgar. Edward was chosen as king and was crowned by his main clerical supporters, the archbishops Dunstan of Canterbury and Oswald of York. (Wikipedia article) 

There is only one type of coin for Edward - similar to Eadgar's reform penny, but substituting "Eadward" for "Eadgar". 

BNJ References:

P. W. P. Carlyon-Britton,  ‘The chronological sequence of the types of Eadweard the Martyr and Æthelræd II’, 16 (1921-22), 5-31

R. H. M. Dolley, ‘Two Anglo-Saxon notes: [1] An enigmatic penny of Edward the Martyr’, 28 (1955-57), 499-504

Ælfthryth looks on as Edward is stabbed to death: from a Victorian edition of Foxe's Book of Martyrs