This gold coin is from the reign of the emperor Constantine VII who ruled the Byzantine Empire for over 40 years from 913 - 959 AD. Approx. specs are (19mm -4.1g).
Obverse: Christ enthroned right hand in benediction, book of Gospels in left hand.
Reverse: Busts of Constantine VII and his son, Romanus II who would succeed him on the throne.
Graded Choice AU by NGC with strike and surface ratings of 5/5 & 4/5 respectively. An excellent example of Byzantine coinage from the 10th century.