Social-democratic party born in 1978 as a Francophone-interests Socialist organization, one of two halves emerged from the since defunct Belgium Socialist Party [Belgische Socialistische Partij (BSP)], the other half presently known as the Flemish-interests "Socialistische Partij Anders" (Socialist Party Differently, sp.a].
The party is led by Paul Magnette and remains Belgium's largest Francophone party in party members [Parti Socialiste (SP)].