In July 1269, King Louis IX of France was planning a campaign in Egypt or the Holy Land. One year later, his fleet landed on Sardinia, and in a war council held on July 13 Louis declared Tunis the target of the crusade. What happened between July 1269 and July 1270 to send the expedition in this unexpected direction is shrouded in secrecy. By expanding the narrative to incorporate Mediterranean‐wide networks of interaction, this chapter identifies several key turning points: the visit of the Dominican linguist Ramon Martí to Tunis in 1269; the attendance of Tunisian envoys at the baptismal ceremony of a French Jew at Saint‐Denis in October; the arrival of a Mongol embassy in Paris toward the end of the year; and the dispatch of an Angevin envoy to Tunis the following April, a month after Louis had lifted the oriflamme at Saint Denis to launch the campaign.