Tacitus, Annals
 

1.33
Germanicus was married to the elder Agrippina, the granddaughter of Augustus, and they had several children... He had a polite and modest personality, a wonderful openness and honesty about him, very different from the proud and hypocritical words and expressions of Tiberius. The mutual enmities between the women added to this; Livia showed a stepmother’s dislike of Agrippina [the Elder]; Agrippina herself was too easily provoked to anger, which would have been apparent if her love and loyalty to her husband had not given her strong-willed character some worthwhile aim.



2.72
[Germanicus was dying, poisoned by Piso.] He turned to his wife. He begged her, by her memory of himself and their children, to put aside her anger, and submit to the savagery of misfortune; he told her, when she returned to the city of Rome, not to anger those in stronger positions by competing for power. This is what he said with others present. In private he said other things, where he was believed to have shown that he was afraid of trouble from Tiberius. Not much later he died.

2.75 Agrippina [the Elder] herself, worn out with grief and physically ill, yet intolerant of every obstacle to revenge, went on board the fleet with her children and the ashes of Germanicus; amid universal pity for this woman of sovereign lineage, her wedded glory wont but yesterday to attract the gaze of awed and gratulatory crowds, now carrying in her bosom the relics of the dead, uncertain of her vengeance, apprehensive for herself, cursed in that fruitfulness which had borne but hostages to fortune.



3.4
The day on which the remains of Germanicus were carried into the Mausoleum of Augustus was characterised either by a deep silence or loud cries of grief. The route through the city was full of people; torches lit up the Campus Martius. The soldiers in armour, the magistrates without badges of office, the people arranged in the tribes were shouting continually that state was destroyed, and that no hope was left; they shouted so readily and openly that you might believe they had not remembered who ruled them. But nothing affected Tiberius more than the enthusiasm for Agrippina [the Elder]; they called her the honour of the country, the only blood-relative of Augustus, the one surviving model of the old values; as they turned to the sky and the gods, they prayed that her children might be unharmed and survive their enemies.



5.3
A letter denouncing Agrippina [the Elder] and Nero was forwarded to Rome... Its wording was of studied asperity, but the offences imputed by the sovereign to his grandson were not rebellion under arms, not meditated revolution, but unnatural love and moral depravity. Against his daughter-in‑law Tiberius dared not fabricate even such a charge, but arraigned her haughty language and refractory spirit; the senate listening in profound alarm and silence... At the same time, the people, carrying effigies of Agrippina [the Elder] and Nero, surrounded the curia, and, cheering for the Caesar, clamoured that the letter was spurious and that it was contrary to the Emperor's wish that destruction was plotted against his house...



6.25
While still sad at the death of Drusus Caesar, men heard also of the death of Agrippina [the Elder], his mother. I think that she had carried on living because her hope of release increased with the death of Sejanus . But when the cruel treatment continued, she died of her free will, unless she was denied food, so that it might seem that she had taken her own life. In any case Tiberius produced the most disgraceful slanders, charging her with immorality and adultery with Asinius Gallus, and saying that she became tired of life once he died.

In fact Agrippina [the Elder], who could not endure anyone equal to her and was greedy for power, had a masculine ambition to make up for feminine defects. Tiberius said that she had died on the same date on which, two years earlier, Sejanus had paid for his crimes, and he thought this should be remembered. He further boasted that she had not been strangled nor thrown down the Gemonian steps . For this the senate decreed thanks and that the 18th October (the date of both deaths) should be celebrated every year with an offering to Jupiter.