"Daylight robbery" is a literal term, coming from the window taxes (you paid more if you had more windows, so all the windows in the Big Houses were bricked up to save money).
"Beyond the Pale" comes from the idea of the supposed horror and ghastliness of living beyond the English Pale in 14th century Ireland. The Pale was the nice protected bit, safe from the Barbarian hordes of the maurauding natives.
A former lecturer of mine insists that the term "Barbaric", which was used by the Romans, describes the non-Latin sounds the uncultured non-Roman rabble made, a "bar bar bar bar blah blah" noise (i.e. they couldn't understand a bleedin' word of it).