For Julius put the fourth letter for the first, and so on through the alphabet; whilst Augustus used the second for the first, the third for the second, and so throughout.

He is said in the greatest difficulties of affairs during the Mutinensian War to have read and written and even declaimed every day.

Tiberius wrote a lyric poem and some Greek verses.
Claudius likewise was skilled in both Greek and Latin, and wrote several books.

But Titus was skilled above all men in the art of writing, and easily imitated any hand he chose; so that he used to say that if he had wished it he might have become a most skilful forger.
All these things are noted by Suetonius in his Lives of the XII.
Caesars..