Hastings' Dictionary of the Bible (1898) & Schaff's Bible Dictionary
CAE'SAR'S HOUSE' HOLD, Phil 4:22, was Paul's phrase for the servants and dependents in the palace of the Roman emperor, some of whom were converts. It is unlikely that any members of the imperial family are meant, although the expression (as Lightfoot remarks) "might include equally the highest functionaries and the lowest menials."