Re. barbarian, Brewer's dictionary of Phrase and Fable (1894) expounds:

Barbarians is certainly not derived from the Latin barba (a beard), as many suppose, because it is a Greek word, and has many analogous ones. The Greeks and Romans called all foreigners barbarians (babblers; men who spoke a language not understood by them); the Jews called them Gentiles (other nations); the Russians Ostiaks (foreigners). The reproachful meaning crept in from the natural egotism of man. It is not very long ago that an Englishman looked with disdainful pity on a foreigner, and the French still retain much of the same national exclusiveness.

"If then I know not the meaning of the voice [words ], I shall be to him that speaketh a barbarian [a foreigner ], and he that speaketh will be a barbarian unto me." - l Cor. xiv. ll.

I also looked up daylight robbery, but it's not there- I've never heard it linked with the window tax, for what that's worth.

Noreen