The Great Wen is a disparaging nickname for London.
The term was coined in the 1820s by William Cobbett, the radical pamphleteer and champion of rural England.
Cobbett saw the rapidly growing city as a pathological swelling on the face of the nation.
The term is quoted in his 1830 work Rural Rides: "But, what is to be the fate of the great wen of all?
The monster, called, by the silly coxcombs of the press, 'the metropolis of the empire?