The sleepy coastal town of Pont l’Abbé in north-west France is about as culturally remote as one can get from the soaring glass towers of the La Défense business district outside Paris, where Jérôme Kerviel worked.

But it was in this small Breton resort of 8,000 that the 31-year-old trader at the centre of Société Générale’s €5bn ($7.4bn) financial scandal got his start in life.