For me its Tat-ee-us, a sort of warped Tacitus. But Oztralians aren't noted
for their command of English. :)
I don't see any immediate similarities between Tatius and Tacitus, except
perhaps that both may well have had uncles done over by an emperor, but it
seems part of the whole Arkat/Arthur, Broyan/Brian Boru, etc. name game.