‘Not fit nor convenient [to] be sent on embassy in the king’s business’

In defiance of contemporary diplomatic theory, which excluded condemned heretics from any involvement in matters connected to diplomacy, Barnes was sent on several missions to Elector John Frederik of Saxony, the League of Schmalkalden, and King Christian III of Denmark. Robert Barnes stayed in Saxony for almost a year from August 1535 until May 1536, and his task was to prevent Philipp Melanchthon from travelling to France. Melanchthon had been invited by King Francis I for a religious conference with the theologians of the University of Paris. The Ambaxiator Brevilogus, published in 1546 by the Archbishop of Toulouse, Bernhard du Rosier, can be regarded as the first textbook on diplomatic practice written in Western Europe. According to du Rosier and Braun, it was not enough for an ambassador to be learned, skilled, eloquent, and prudent; additionally, he should be temperate, discreet, honest, just, sober, pious, liberal, patient, generous, magnanimous, calm and brave.