The prominent ancient historian Edward Togo Salmon notes in his work , A history of the Roman world from 30 B.C. to A.D. 138 : `` In the whole twenty two years of Tiberius ' reign , not more than fifty-two persons were accused of treason , of whom almost half escaped conviction , while the four innocent people to be condemned fell victims to the excessive zeal of the Senate , not to the Emperor 's tyranny '' . The prominent ancient historian Edward Togo Salmon notes in his work , A history of the Roman world from 30 B.C. to A.D. 138 :