Decimus Iunius Iuvenalis (ˈdɛkɪmʊs ˈjuː.ni.ʊs ˈjʊ.wɛ.naː.lɪs), known in English as Juvenal (ˈdʒuːvənəl), was a Roman poet active in the late first and early second century AD. He is the author of the collection of satirical poems known as the Satires. The details of the author's life are unclear, although references within his text to known persons of the late first and early second centuries AD fix his earliest date of composition. One recent scholar argues that his first book was published in 100 or 101. Because of a reference to a recent political figure, his fifth and final surviving book must date from after 127. Juvenal wrote at least 16 poems in the verse form dactylic hexameter. These poems cover a range of Roman topics. This follows Lucilius—the originator of the Roman satire genre, and it fits within a poetic tradition that also includes Horace and Persius. The Satires are a vital source for the study of ancient Rome from a number of perspectives, although their comic mode of expression makes it problematic to accept the content as strictly factual. At first glance the Satires could be read as a critique of pagan Rome. That critique may have ensured their survival in the Christian monastic scriptoria although the majority of ancient texts did not survive.