Caesar's Commentaries were probably intended to seem to be "impartial"
dispatches sent back to Rome reporting (perhaps on a year-by-year installment
basis) his progress in subduing those fearful barbarians up there who had always
terrified Romans. Caesar himself was very much into partisan politics, but
keeping a third-person system of reference, referring to himself only
occasionally and then as "Caesar," very possibly was a way of making the
objectivity level of what he wrote seem higher (although we know he put the
best face on all of the "facts" whenever possible).