Though grateful to England for the sanctuary it offered, the French Communards found London a problem. Typical in his feelings of love-hate was the writer-revolutionary Jules Vallès, whose bestseller Londres dans la rue (very strong on the hate) should be read in tandem with his Letters, where other sentiments come through.

'London is lugubrious,' he says. 'The rain is black and the inhabitants are a gloomy lot. Away from the busy streets there's a terrible sadness; and the busy streets themselves are an avalanche of crowds and noise, like a rabble army in retreat. But there's also a grandeur about it all, and that feeling of complete freedom to do anything one wants, to be poor or to be rich. I'd rather live in London than Geneva, Lausanne, The Hague, Brussels, Nantes or Rouen. A walk round London really shakes you up: even Paris will seem tame after this.'

To a fellow Communard who has chosen Lugano and isn't too happy, he says: 'Plunge into a big city. You'll rust more surely in the sunshine than in fog. More sick men would survive if, from their bed, they could see the street. So come to London. I absolutely recommend this black town. London, the immense London, with the British Museum in the middle of it.'

The BM he describes variously as 'a huge and unimaginable bonus' and 'a town in itself, full of riches with benign administrators'. They are serious and efficient, he says, but ...