Orsini affair

The Orsini affair comprised the diplomatic, political and legal consequences of the "Orsini attempt" (French: attentat d'Orsini): the assassination attempt made on 14 January 1858 by Felice Orsini, with other Italian nationalists and backed by English radicals, to assassinate Napoleon III in Paris.

In the United Kingdom the Palmerston government fell within a month; and some related trials of radicals ended without convictions, as British public opinion reacted against French pressure.

After the assassination attempt, Camillo Benso in Italy was able to make France his ally during the Risorgimento.

The attack carried out by Orsini and his group was justified by its supporters in terms of the unification of Italy, a cause that Napoleon III was perceived as blocking. In the middle of the nineteenth century, this nationalist movement in favour of a united Italy, something that had not existed since Late Antiquity, drew widespread support from intellectuals, and was also championed by violent extremists. The expatriate Italian leader Giuseppe Mazzini worked a network of activists and fundraisers from London.

British politics and diplomacy of this period assumed that political exiles and refugees should be given asylum. In the period 1823 (de facto) to the Aliens Act 1905, the United Kingdom did not attempt to control or register immigrants. The Orsini affair was a severe test of the consequences of this policy. Besides Mazzini, Alexandre Auguste Ledru-Rollin, Lajos Kossuth and Alexander Herzen had moved to London: and Napoleon III suspected Mazzini and Ledru-Rollin of being behind a series of attempts by Italians to kill him, of which Orsini's was only the most recent. The existing British law on conspiracy made it a misdemeanour, and there was no extradition.

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