Tricennial

Some manuscripts of Eusebius' Life of Constantine contain not only the four books of the Life and Constantine's Speech to the Assembly of the Saints but also two speeches which are conventionally known by a single title as Laus Constantini, Laudes Constantini, De laudibus Constantini, or the "Tricennial Oration," and which all editors of Eusebius so far have published as a single work.

(vi) The employment of Constantine's high-crested helmet in the gold coinage of Constantius in his tricennial issues...