Herennia Etruscilla was the wife of Trajan Decius and mother of Herennia Etruscus and Hostilian. As with most third century Roman empresses, very little about her is known. She lived to sink into obscurity after her husband and sons perished. She probably retained the title of Augusta under Trebonianus Gallus and coins may have been struck for her as late as AD 253.

Main Roman Coin Book and Other References:

RIC = Mattingly, Harold    The Roman Imperial Coinage
BMC = Coins of the Roman Empire in the British Museum
RSC = Seaby, H A    Roman Silver Coinage
RCV = Sear, David R    Roman Coins and Their Values
Cr = Crawford, Michael    The Roman Republican Coinage
SB = Sear, David R    Byzantine Coins and Their Values
S = Coins of England and the United Kingdom
WW = Wildwinds.com (reference & attribution site)