The Flowers of Evil (Les Fleurs du mal, 1857) is the most celebrated and most influential collection of verse in the history of modern French poetry. Its author, Charles Baudelaire (1821–67), is seen as the embodiment of a sensibility we regard as 'modern'. T.S. Eliot called him 'the greatest exemplar of modern poetry in any language'.

Baudelaire's modernism is based on the experience of city life. The spectacular transformation of Paris by Baron Haussmann during Napoleon III's Second Empire (1852–70) not only reshaped the city physically but also broke down or blurred boundaries of every kind – cultural, social, perceptual. The dramatically new patterns of urban life dislocated and fragmented traditional relationships and frames of reference. Many people felt they had lost Paris and were dwelling in someone else's city.

Baudelaire called for a new aesthetic to match the challenges of 'modernity'. A new mode of representation was needed, he wrote, to match a new mode of perception. The exemplary artist would capture the thrill of the new – the speed and flux, the dizzy sense of change, that characterised modernity. Modern beauty, he wrote, lay not in the untouched scenes of nature prized by the Romantics, nor in the timeless themes of the classical tradition, but in the artificial creations of city life. Indeed, the city, being man-made, represented art itself.