Following the bloody battles of Magenta and Solferino, both French victories, Napoleon thought the war too costly to continue and made a separate peace behind Cavour's back in which only Lombardy would be ceded.
Pärast veriseid Magenta ja Solferino lahinguid, mõlemad Prantsusmaale võidukad, pidas Napoleon sõja jätkamist liiga kulukaks ja tegi eraldirahu Cavouri selja taga, millega pidi loovutatama ainult Lombardia.