When Louis Napoleon (Napoleon III) seized complete power in 1851, establishing an anti-parliamentary constitution, Hugo openly declared him a traitor to France. He relocated to Brussels, then Jersey, from which he was expelled for supporting a Jersey newspaper that had criticised Queen Victoria and finally settled with his family at Hauteville House in Saint Peter Port, Guernsey, where he would live in exile from October 1855 until 1870.
While in exile, Hugo published his famous political pamphlets against Napoleon III, Napoléon le Petit and Histoire d'un crime. The pamphlets were banned in France, but nonetheless had a strong impact there. He also composed or published some of his best work during his period in Guernsey, including Les Misérables, and three widely praised collections of poetry (Les Châtiments, 1853; Les Contemplations, 1856; and La Légende des siècles, 1859).
He convinced the government of Queen Victoria of the United Kingdom to spare the lives of six Irish people convicted of terrorist activities and his influence was credited in the removal of the death penalty from the constitutions of Geneva, Portugal and Colombia. He had also pleaded for Benito Juárez to spare the recently captured emperor Maximilian I of Mexico but to no avail. His complete archives (published by Pauvert) show also that he wrote a letter asking the USA, for the sake of their own reputation in the future, to spare John Brown's life, but the letter arrived after Brown was executed.
Although Napoleon III granted an amnesty to all political exiles in 1859, Hugo declined, as it meant he would have to curtail his criticisms of the government. It was only after Napoleon III fell from power and the Third Republic was proclaimed that Hugo finally returned to his homeland in 1870, where he was promptly elected to the National Assembly and the Senate.