The only widely accepted mention of Valerius Flaccus by his contemporaries is by Quintilian, who laments the recent death of "Valerius Flaccus" as a great loss; as Quintilian's work was finished about 90 AD, this traditionally gives a limit for the death of Valerius Flaccus. Recent scholarship, however, puts forward an alternative date of about 95AD, and definitely before the death of Domitian in 96AD. It has been claimed that he was a member of the College of Fifteen, who had charge of the Sibylline books, based on a reference in his work to the presence of a tripod in a "pure home". The assumption that this indicates he himself was a member, however, has also been contested. A contested mention of a poet of the name "Valerius Flaccus" is by Martial, who refers to a native of Padua. A subscription in the Vatican manuscript adds the name Setinus Balbus, a name which suggests that its holder was a native of Setia in Latium, however it is not clear if this inscription refers to "Valerius Flaccus" or someone else. The connection of this "Valerius Flaccus" to Gaius Valerius Flaccus has been contested under the assumption that Martial was referring to the friend's financial strife, and that Gaius Valerius Flaccus was a member of the College of Fifteen, and therefore likely to have been wealthy.
''Argonautica''
Valerius Flaccus' only surviving work, the Argonautica, was dedicated to Vespasian on his setting out for Britain. It was written during the siege, or shortly after the capture, of Jerusalem by Titus in 70 AD. As the eruption of Vesuvius in 79 AD is alluded to, its composition must have occupied him a long time. The Argonautica is an epic poem probably intended to be in eight books written in traditional dactylic hexameters, which recounts Jason's quest for the Golden Fleece. The Argonautica was lost until 1411, when the first 4½ volumes were found at St Gall in 1417 and published at Bologna in 1474. The poem's text, as it has survived, is in a very corrupt state; it ends so abruptly with the request of Medea to accompany Jason on his homeward voyage, that it is assumed by most modern scholars that it was never finished. It is a free imitation and in parts a translation of the Argonautica of Apollonius of Rhodes, "to whom he is superior in arrangement, vividness, and description of character". The familiar subject had already been treated in Latin verse in the popular version of Varro Atacinus. The object of the work has been described as the glorification of Vespasian's achievements in securing Roman rule in Britain and opening up the ocean to navigation. In 1911, the compilers of the Encyclopædia Britannica remarked, More modern analysis has been more accepting of Valerius Flaccus' style, noting how it fits in the "long and energetic Roman tradition of appropriation of the golden age and iron age myths" and commenting on his narrative technique: