Although the chief persecutors of the Jews had disappeared, the unhappy conditions created by them remained. The exclusive laws of Castile and the bull of Pope Benedict were still in force. Ferrer's proselytizing campaigns had severely crippled the Spanish, and even foreign communities. In Portugal alone they met with no success. The Portuguese ruler, Don João I, had other interests to pursue than the conversion of Jews. He was then occupied in that first conquest on the coast of Africa, opposite to Portugal, which laid the foundation of the subsequent maritime supremacy of the Portuguese. When Vincent Ferrer petitioned King João for permission to come to Portugal in order to make the pulpits and streets resound with his dismal harangues on the sinfulness of the world and the blindness and obstinacy of the Jews, the Portuguese king informed him that he "might come, but with a crown of red-hot iron on his head." Portugal was the only refuge on the Pyrenean peninsula from the proselytizing rage of the flagellant preacher, and many Spanish Jews who had the means of escaping fled thither. Don Judah Ibn Yachya-Negro, held in high esteem by King João I, and, perhaps, appointed by him chief rabbi of Portugal, represented to him the horrors of enforced baptism, and the necessary insincerity of the professions of unwilling converts. The king consequently issued his commands that the immigrant new-Christians should not be interfered with or delivered up to Spain. In other parts of Europe, where the fanatical Dominican had been, or whither reports of his deeds or misdeeds had penetrated, the Jews were forced to drain the cup of bitterness to the dregs. In Savoy, which Vincent Ferrer had visited, they were obliged to hide themselves with their holy books in mountain caves. In Germany, persecutions of Jews had always found a congenial soil, and they were promoted by the anarchy which prevailed during the reign of Sigismund and the sessions of the council of Constance. Even the Italian communities, though for the most part undisturbed, lived in continual anxiety, lest the movement strike a responsive chord in their politically distracted land. They convened a great synod, first at Bologna, then at Forli (1416-1418), to consider what measures might be adopted to avert the threatened danger.