Apostate priest. He was suspended by ecclesiastical authorities for immorality, and later imprisoned by the pontifical government for revolutionary agitation. He gave anti–Catholic lectures in London, England; exposed by Venerable John Henry Newman, he brought a libel action in 1852, in which Newman was fined £100, owing to the anti–Catholic prejudices of the judges. Achilli afterwards became utterly discredited, and the incident caused a revulsion in favor of Newman.
- may have commited suicide