He then retired from politics and spent many years in Belgium as a professor of mnemonics and a prolific author on philological subjects.
His family were strolling players who traveled around Italy giving mnemonic demonstrations and spreading the gospel.
[4] Zanardelli stayed for long periods in Naples, and became active in Giuseppe Mazzini's movement for Italian unification.
In August 1872 he attended the constitutive congress of the Federazione Alta Italia dell'Associazione Internazionale dei Lavoratori (FIAIL: Northern Italian section of the International Workingmen's Association) in Rimini, then was active in Venice where he and Pietro Magri co-founded the local workers' Federation.
[1] Zanardelli prepared an almanac to be printed at the start of 1873 that gave the biographies of prominent people of the International who had died, arranged in alphabetical order.
In November 1875 Zanardelli, Nabruzzi and Joseph Favre founded the Lake Lugano IWA section.
[1] Encouraged by Benoît Malon, Zanardelli and Nabruzzi published their Almanacco del proletario per l'anno 1876 in which they criticized the 1874 insurrection.
[7] During a news conference organized by his section in April 1876 Zanardelli spoke in favor of fighting for electoral reform.
[9] On 3 November 1879 he spoke at a protest meeting arranged by the German club against the arrest in Germany of the anarchists Just and Kaufmann.
He finally left the socialist and anarchist movement, moved to Brussels and devoted himself exclusively to the study of philology.