The Bustuarii (sing. bustuarius) were a kind of gladiators in Ancient Rome, who fought about the bustum, or pile of a deceased person, in the ceremony of his obsequies.
At first, the practice was to sacrifice captives on the tomb, or at the bustum of their warriors: instances of which are in Homer, at the obsequies of Patroclus, and among the Greek tragedians. Their blood was supposed to appease the infernal gods, and render them propitious to the remains of the deceased. In later ages, this custom appeared too barbarous; and in lieu of these victims, they appointed gladiators to fight, whose blood, it was supposed, might have the same effect.
According to Valerius Maximus and Florus, Marcus and Decimus, sons of Brutus, were the first, at Rome, who honored the funerals of their father with these kind of spectacles, in the year of Rome 489. Some authors in the previous century claimed that the Romans borrowed this custom from the Etrurians, though the evidence now points to Campania, and to a campanian influence and thus to a Greek borrowing since the Greeks settled in Campania since the eighth century BC.
This article incorporates text from a publication now in the public domain: Chambers, Ephraim, ed (1728). "article name needed". Cyclopædia, or an Universal Dictionary of Arts and Sciences (first ed.). James and John Knapton, et al.
The original article can be found at Bustuarii and the edit history here.