The Romans were severely tested in the three Punic wars but their struggles against a worthy, if barbaric and perfidious, enemy were a necessary feature of their emergence as the dominant power.

ECONOMIST: Myth and the making of history

My wife knows me as a perfidious stock picker.

FORBES: Do As I Say

But then the French have always had a soft spot for perfidious Albion's northern neighbours.

ECONOMIST: Perfidious Albion��and the auld ally

Or has the NHS row confirmed a deeper Tory hunch: that just as leopards have spots, Lib Dems are perfidious and sneaky, making the coalition an obstacle to bold policymaking?

ECONOMIST: Bagehot