At the same time, the pope sent cardinal Bernardino Spada as plenipotentiary in an effort to resolve the crisis. Spada successfully negotiated a truce but when the pope's military leaders became aware that the dukes were massing troops to counter their own (in case discussions with Spada came to naught), Urban VIII declared the articles of peace null and void and claimed Spada had negotiated them without his consent. Spada later published a manifesto detailing his version of events which, according to contemporary John Bargrave, many accepted to be the truth.