Herennius Etruscus was the son of 
Trajan Decius and older brother of 
Hostilian.  Decius elevated Herennius to co-emperor in 
251. Herennius died with his father in the 
Battle of Abrittus, after he was hit by an arrow; they were the first two emperors to be killed by a foreign army in battle.  Though the army proclaimed 
Trebonianus Gallus emperor, Herennius was succeeded by Hostilian.
 
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