As with most third-century Roman empresses, very little is known about her. The date and place of her birth are not known for certain. She was probably from a senatorial family of
Herennia gens. It is assumed that her ancestors settled in
Etrurian lands. Herennia married Decius probably before 230, In order to gain popular support, Trebonianus Gallus retained Herennia Etruscilla as '''' (empress-mother) and elevated
Hostilian to , making him co-emperor alongside Trebonianus Gallus himself. Hostilian died in July 251, either from a
plague or murder, after which Trebonianus Gallus' son
Volusianus, was raised to . In November 251 AD, Herennia survived the epidemic, in which her son
Hostilian died, retained the role of Augusta, despite any familial ties to Gallus and lived until 253 AD, corresponding to the end of his reign. ==Numismatics==