Being childless , their heir was Justinian I. He was the nephew and adoptive son of Justin .
Procopius also claims that both members of the imperial couple attained the throne in the closing years of their lives .
Being childless , members ' heir was Justinian I. He was the nephew and adoptive son of Justin .
Procopius also claims that both members of the imperial couple attained the throne in the closing years of their lives .