Complex sentence: Whereas his father, Louis Joxe, was Justice Minister of Charles de Gaulle, Pierre Joxe joined François Mitterrand's team in the Convention of the Republican Institutions and joined the Socialist Party ("Parti socialiste" or PS) in 1971.
Split into simpler sentences: Whereas his father, Louis Joxe, was Justice Minister of Charles de Gaulle, Pierre Joxe joined François Mitterrand's team in the Convention of the Republican Institutions. This one joined the Socialist Party ("Parti socialiste" or PS) in 1971.