"princes walled up alive"
The most famous Italian to apparently be immured (that's the official term for killing somebody by walling them within a building, by the way) was Ugolino della Gherardesca, a 13th century nobleman. He was accused of treason and locked up in a tower with his sons and grandsons, after which the key was allegedly thrown away and the five were left to starve to death. Popular myth also has Ugolino eating the corpses of his dead offspring after they themselves died, giving him the nickname "the Cannibal Count". Just another cheerful day in Medieval Italy!