Valerius Maximus, Memorable Deeds and Sayings 2.7.init.

venio nunc ad praecipuum decus et ad stabilimentum Romani imperii, salutari perseverantia ad hoc tempus sincerum et incolume servatum, militaris disciplinae tenacissimum vinculum, in cuius sinu ac tutela serenus tranquillusque beatae pacis status adquiescit.

I now come to the Roman Empire’s chief glory and mainstay, which has been preserved entire and unharmed, through beneficial steadfastness, to the present time, namely the firmest bond of military discipline: in its bosom and under its protection rests the fair and tranquil state of blessed peace.