A falling out with the Prince of Wales led to Brummell's downfall; his famous remark "Alvanley, who's your fat friend?" (referring to the Prince - who had just cut him) probably didn't help. Brummell fled England in 1816 as the result of gambling debts. His friends arranged for him to become British consul at Caen in France, but unfortunately the post was abolished. He died penniless and insane in Caen in 1840.
Jules Barbey d'Aurevilly wrote an essay about him, On Dandyism and George Brummell.