Suetonius, Caligula (§3):
It is pretty well agreed that all of the virtues of body and mind were conjoined in Germanicus as they had been in no one else: exceptional form and fortitude, an intelligence excelling in both types of eloquence and learning, a singular benevolence and the marvelous, effective eagerness to garner people’s favor and deserve their love.
The thinness of his legs was less suited to his form, but that too was remedied by assiduous horse riding after meals. He often assaulted an enemy face to face. He even gave triumphal speeches, and among the other monuments of his studies, he left behind some Greek comedies. Both at home and abroad, to free and to federated cities, he went as a citizen without lictors. If he ever recognized the tombs of famous men anywhere, he would give sacrifices to their Manes. As he was about to bury the old and dispersed remains of those slain in the Varian disaster, he was the first to embark upon collecting them and carrying them with his own hand. Even to his detractors, whoever they were and for whatever cause he had acquired them, he was so gentle and kind that when Piso rescinded his decrees and violated his client-patron relations, he did not take it into his mind to be angry with him until he found out that he was being assailed by poisons and curses; and even then, he did not take it any farther than renouncing his friendship with Piso in the approved ancient manner, and entrusted the revenge, should anything befall him, to his domestics.
Omnes Germanico corporis animique virtutes, et quantas nemini cuiquam, contigisse satis constat: formam et fortitudinem egregiam, ingenium in utroque eloquentiae doctrinaeque genere praecellens, benivolentiam singularem conciliandaeque hominum gratiae ac promerendi amoris mirum et efficax studium. Formae minus congruebat gracilitas crurum, sed ea quoque paulatim repleta assidua equi vectatione post cibum. Hostem comminus saepe percussit. Oravit causas etiam triumphalis; atque inter cetera studiorum monimenta reliquit et comoedias Graecas. Domi forisque civilis, libera ac foederata oppida sine lictoribus adibat. Sicubi clarorum virorum sepulcra cognosceret, inferias Manibus dabat. Caesorum clade Variana veteres ac dispersas reliquias uno tumulo humaturus, colligere sua manu et comportare primus adgressus est. Obtrectatoribus etiam, qualescumque et quantacumque de causa nanctus esset, lenis adeo et innoxius, ut Pisoni decreta sua rescindenti, clientelas divexanti non prius suscensere in animum induxerit, quam veneficiis quoque et devotionibus impugnari se comperisset; ac ne tunc quidem ultra progressus, quam ut amicitiam ei more maiorum renuntiaret mandaretque domesticis ultionem, si quid sibi accideret.