sentences:  The PNB was formed in the aftermath of split between federalists and nationalists within the Breton Autonomist Party (PAB), following the Congress of Guingamp in August 1931.Following the collapse of the PAB, the federalists led by Morvan Marchal formed the Breton Federalist League; the nationalist faction, led by Olier Mordrel, decided to found a new party with a clearly nationalist agenda, namely seeking Breton independence from France.This revived the programme of the previous Breton Nationalist Party, which had existed from 1911-1914.