E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
Aller à Rouen. To go to ruin. The French are full of these puns, and our merry forefathers indulged in them also.
(1) Il a fait son cours à Asnières. He knows nothing; he graduated at Dunse [Dunce] College.
(2) Aller à Cachan. To give leg-bail, or se cacher [de ses créanciers]; to go to Hyde [Hide] Park.
(3) Aller à Dourdan. To go to be whipped (douder, être battu); to be on the road to Flogny.
(4) Vous êtes de Lagny, vous navez pas hâte. I see you are a man of Laggon. Dont hurry yourself, Mr. Slowcoach.
(5) Il est de Lunel, Il a une chambre à Lunel, Il est des Luniers dOrléans, or Il est Logé à la Lune. He is a lunatic.
(6) Envoyer à Mortaigne. To be slain, or sent to Deadham.
(7) Aller à Patras. To die; to be gathered to ones fathers (ad patres).
(8) Aller à Versailles. To be going to the bad. Here the pun is between Versa-illes and renverser. This wretched pun is about equal to such a phrase as Going to Downham.
The Bloody Feast of Rouen (1356). Charles the Dauphin gave a banquet to his private friends at Rouen, to which his brother-in-law Charles the Bad was invited. While the guests were at table King Jean entered the room with a numerous escort, exclaiming, Traitor, thou art not worthy to sit at table with my son! Then, turning to his guards, he added, Take him hence! By holy Paul, I will neither eat nor drink till his head be brought me! Then, seizing an iron mace from one of the men-at-arms, he struck another of the guests between the shoulders, exclaiming, Out, proud traitor! by the soul of my father, thou shalt not live! Four of the guests were beheaded on the spot.