The CTLN formed in October 1943 following the Nazi occupation of Tuscany the previous month. Five anti-fascist groups united under the banner of the CTLN. The largest of these groups was the Italian Communist Party (PCI) followed by the Italian Socialist Party (PSI). CTLN also incorporated Partito d'Azione (PDA), the Christian Democracy (DC), and the Italian Liberal Party (PLI). The group initially met clandestinely in Florence in an artisan workshop in San Frediano and in the offices of local socialist, Natale Dall'Oppio whilst Tuscany remained under occupation.