On the usual dating, the beginning of Juvenal's literary career coincided with Martial's later years: the composition of the first satire, which contains a reference to the trial of Marius Priscus in A.D. 100, was probably contemporaneous with the epigrammatist's retirement to Spain. Martial praised three emperors, and when it was safe to do so, condemned the memory of the first: but it is essentially the age of Domitian in which he moves. His work spans the last quarter century, a medley of adulation, obscenity, and off-hand observation on a tired, neurotic world. Perhaps gloating, he writes to Juvenal from Spain, comparing town and country: he is at ease, while Juvenal is harassed in the city (12.18). Juvenal, strangely impersonal despite his spleen and violence, has nothing in reply. For one obsessed with the world of the dead, friendship could have had few attractions. Tradition has it that he mellows with time: in fact he simply writes less well after the vitriolic ninth satire, and the paradigmatic, rhetorical tenth. In Satire 15 the venom returns, but it is for his first two books, Satires 1–6, that he is chiefly celebrated. With time, his manner becomes less taut and less intense, more leisurely and reflective; the later Juvenal is a declaimer's poet, preoccupied with theses. In his earlier work he castigated vice and poured scorn on the insufficiencies of virtue, rejecting the ironic manner of Horace and the sermons of Persius, to adopt a deeply pessimistic, hysterically tragic stance. Martial provided him with material and characters, but the mood is all his own.