The arrival of the Gierek team meant the final generational replacement of the ruling communist elite, a process begun in 1968 under Gomułka. Many thousands of party activists, including important elder leaders with background in the prewar Communist Party of Poland, were removed from positions of responsibility and replaced with people whose careers formed after World War II. Much of the overhaul was accomplished during and after the VI Congress of the PZPR, convened in December 1971. The resulting governing class was one of the youngest in Europe. The role of the administration was expanded at the expense of the party, according to the maxim "the party leads, the government governs". Throughout the 1970s, the most highly visible member of the top leadership after Gierek was Prime Minister Piotr Jaroszewicz. From May 1971, Gierek's rival party politician Mieczysław Moczar was increasingly marginalized.