In 1845, wishing to complete his education, Maestri undertook a lengthy visit to Paris and London. He met up with Giuseppe Mazzini, who had been exiled in London, living in conditions of some material hardship, since 1837, following the failure of uprisings against Austrian hegemony earlier in the 1830s. Mazzini became a prodigious and inspiring author during his time in England, and by the time Maestri met him in London he was an iconic figure among young Italian men committed to the causes of what was known as and impatient for revolution. Maestri later reported that he had been favourably impressed by Mazzini, whom he thought a "giovine eccellente" ("excellent young man"). He nevertheless later claimed to have identified a risk, even in 1845, that Mazzini might succumb to "the usual tendency of [brilliant men], and substitute thoughts based on theory for the need for [simple] insurrectionary action".