Rupert Christiansen’s City of Light opens on the evening of 5 January 1875, with the inauguration of Paris’s new opera house, designed by Charles Garnier ‘in a style of unabashed grandeur’, with its gilded and mirrored salons, shimmering candelabra and marbled colonnades, mosaics, statues, frescoes and ‘flaming gas torches enhancing a central stairwell that turned the ascending and descending audience into an impressive spiralling spectacle’.