The Party of Socialists and Democrats (Italian: Partito dei Socialisti e dei Democratici PSD) is a social-democratic political party in San Marino. It is a member of the Socialist International and its current-day Italian counterpart is the Democratic Party.The PSD was formed in 2005 by a merger of the Sammarinese Socialist Party (PSS) the oldest political party in the country and the Party of Democrats (PD).