"As we know them, the Mithraic mysteries are a Roman phenomenon that flourished in the Roman Empire from the second century C.E. on." p. 199.
Meyer, M.W. ed. (1987). The Ancient Mysteries. Philadelphia: University of Pennsylvania Press.
"The Roman cult of Mithras, documented from the end of the first century CE, spread widely throughout the Roman empire over the next three hundred years." p. 188.
Martin, L. H. (2005). Performativity, Narrativity, and Cognition: Demythologizing the Roman Cult of Mithras. In Braun, Willi (Ed). Rhetorics and Realities In Early Christianities. Waterloo: Wilfrid Laurier University Press, pp. 187-217.
"A second impouls behind the growth of pagan monotheism was the influence of Christianity itself. Jan Bremmer has noted how, from the second century onwards, apparently new mystery religions appeared, devoted to gods who die and resurrect, such as Atis, or act as personal saviors, such as Mithras." p. 89
Hutton, R. (2003). Witches, Druids, and King Author. London: Hambledon and London.
"Archaeologically, the cult of Mithras first appears in the Roman world in the Flavian-Trajanic period [well after Jesus], when traces of it (inscriptions, mithraea) are suddenly found at several widely separated sites, in Rome, Germania Superior, Raetia/Noricum, Moesia Inferior, Judea. The contexts are those we might expect: the military, the provincial toll system, harbor towns; the big surprise is Alcimus at Rome, the rich slave-bailiff of Tiberius Claudius Livianus, praetorian prefect from ad 102 (ILS 4199). No less striking is the fact that the first clear literary reference dates from the same period: the poet Statius refers to Mithras, identified with solar Apollo, twisting the recalcitrant horns in a Persian cave, Persaei sub rupibus antri/indignata sequi torquentem cornua Mithram (Thebaid 719f.), a passage probably written in the mid-80s. p 395."
Gordon, Richard. (2007) Institutionalized Religious Options. In Rüpke, Jörg. (ed). Companion to Roman Religion. Oxford: Blackwell Publishing, pp. 392-405.