To what extent this animosity between the two ladies was carried it is difficult to determine. Some historians claim that it resulted in placing another awful crime to Livia's account. Germanicus died in Seleucia in the thirty-fourth year of his age, of some mysterious malady; and there were many who at once whispered that Livia had been the means of bringing about his death by poisoning. But there is no proof of this, and a careful study of the known facts causes it to seem improbable. There was no motive for such an act, beyond the fact that the husband of Agrippina was exceedingly popular with the army and the people; but this was offset by his undoubted and enthusiastic devotion to Tiberius. The facts, so far as they are now ascertainable, are these: Piso, who was Proconsul of Syria, was instigated by his wife Plancina to acts of disrespect and animosity against Germanicus and Agrippina. This woman, who was of an exceedingly masculine temperament,--as is shown among other things by her habit of taking part in the exercises of the cavalry,--was a great favorite with Livia and shared her closest confidence. Plancina is said to have kept about her a woman named Martina, who had an evil reputation as being expert in the use of poisonous drugs, but of whose existence nothing more is known than the little that is told in this connection, Germanicus, on his deathbed, declared that he was cut short in his career by the dark devices of a woman. The news of his decease did not affect Livia with the same degree of sorrow as it did the populace; which fact tended to strengthen suspicion in the minds of the latter. But all this proves nothing, even though Piso, despairing of acquittal, destroyed himself during his trial, after having written a letter protesting his innocence. Nor does the fact that Plancina was protected by Livia furnish any proof that the aged and much-maligned empress was guilty of instigating the crime, if crime it was.