Following years of mistreatment, the Taínos began to adopt suicidal behaviors, with women aborting or killing their infants and men jumping from the cliffs or ingesting untreated cassava, a violent poison. Eventually, a Taíno Cacique named Enriquillo managed to hold out in the Baoruco Mountain Range for thirteen years, causing serious damage to the Spanish, Carib-held plantations and their Indian auxiliaries. Hearing of the seriousness of the revolt, Emperor Charles V (also King of Spain) sent captain Francisco Barrionuevo to negotiate a peace treaty with the ever-increasing number of rebels. Two months later, after consultation with the Audencia of Santo Domingo, Enriquillo was offered any part of the island to live in peace.

Answer this question, if possible (if impossible, reply "unanswerable"): Who was sent to negotiate a peace treaty with the rebels?
Francisco Barrionuevo