In February 1817 he settled at Marlow with Mary and Claire. Claire, as a result of her intrigue with Byron--of which the fruit was a daughter, Allegra, born in January--was now a permanent charge on his affectionate generosity. It seemed that their wanderings were at last over. At Marlow he busied himself with politics and philanthropy, and wrote 'The Revolt of Islam'. But, partly because the climate was unsuitable, partly from overwork in visiting and helping the poor, his health was thought to be seriously endangered. In March 1818, together with the five souls dependent on him--Claire and her baby, Mary and her two babies (a second, Clara, had been born about six months before)--he left England, never to return. Mary disliked hot weather, but it always put Shelley in spirits, and his best work was done beneath the sultry blue of Italian skies, floating in a boat on the Serchio or the Arno, baking in a glazed cage on the roof of a Tuscan villa, or lying among the ruins of the Coliseum or in the pine-woods near Pisa. Their Italian wanderings are too intricate to be traced in detail here. It was a chequered time, darkened by disaster and cheered by friendships. Both their children died, Clara at Venice in 1818, and William at home in 1819. It is impossible not to be amazed at the heedlessness--the long journeys in a rough foreign land, the absence of ordinary provision against ailments--which seems to have caused the death of these beloved little beings. The birth in 1819 of another son, Percy (who survived to become Sir Percy Shelley), brought some comfort. Claire's troubles, again, were a constant anxiety. Shelley worked hard to persuade Byron either to let her have Allegra or to look after his daughter properly himself; but he was obdurate, and the child died in a convent near Venice in 1822. Shelley's association with Byron, of whom, in 'Julian and Maddalo' (1818), he has drawn a picture with the darker features left out, brought as much pain as pleasure to all concerned. No doubt Byron's splenetic cynicism, even his parade of debauchery, was largely an assumption for the benefit of the world; but beneath the frankness, the cheerfulness, the wit of his intimate conversation, beneath his careful cultivation of the graces of a Regency buck, he was fundamentally selfish and treacherous. Provided no serious demands were made upon him, he enjoyed the society of Shelley and his circle, and the two were much together, both at Venice and in the Palazzo Lanfranchi at Pisa, where, with a menagerie of animals and retainers, Byron had installed himself in those surroundings of Oriental ostentation which it amused him to affect.