When was Saint Tarcisius born?

A:

A tradition dating from the sixth century says that St. Tarcisius was an youth whose fidelity and courage impressed the leaders of the Church during the persecution of Valerian, emperor of Rome from 253 to 260 CE. Legend says that he was about thrteen years old at the time of the persecutions, meaning that he could have been born around 240 to 247 CE. No further information is available as to when Tarcius lived, or even if he really existed. All we really have is a poem by Pope Damasus, who might simply have sought to inspire the faithful in the time of his own century, by creating or expanding on a legend that provided an example for people to look up to.

A more recent adition to the legend of Tarcisius was made by Cardinal Wiseman in his novel Fabiola, or the Church in the Catacombs, where Tarcisius is portrayed as a young acolyte.