The treatise is addressed to Marcus Claudius Marcellus .
The treatise is thus will have been composed before Marcellus ' death in 23 BC ( and possibly at a time when its addressee was preparing to go out on campaign ) .
The treatise is addressed to Marcus Claudius Marcellus , and thus will have been composed before Marcellus ' death in 23 BC ( and possibly at a time when its addressee was preparing to go out on campaign ) .