According to Darrell Bock , the title of apostola apostolorum first appears in the 10th century .
Katherine Ludwig Jansen says she found no reference to it earlier than the 12th , by which time it was already commonplace .
According to Darrell Bock , the title of apostola apostolorum first appears in the 10th century , but Katherine Ludwig Jansen says she found no reference to it earlier than the 12th , by which time it was already commonplace .