In spite of this natural but impolitic segregation, the Mudéjares gradually became denationalized and assimilated themselves in many ways to the population by which they were surrounded. In time they forgot their native language and it became necessary for their learned men to compile law-books in Castilian for the guidance of their alcadís. Quite a literature of this kind arose and, even after the final expulsion, as late as the middle of the seventeenth century, among the refugees in Tunis, a manual of religious observances was composed in Spanish, the author of which lamented that even the sacred characters in which the Korán was written were almost unknown and that the rites of worship were forgotten or mingled with usages and customs borrowed from the Christians.[195] The Mudéjares even sympathized with the patriotic aspirations of their Castilian neighbors, as against their independent brethren. When, in 1340, Alfonso XI returned in triumph to Seville, after the overwhelming victory of the Rio Salado, we are told how the Moors and their women united with the Jews in the rejoicings which greeted the conqueror.[196] Even more practical was the response to the appeal of the Infante Fernando, in 1410, when he was besieging Antequera, one of the bulwarks of Granada, and was in great straits for money. He wrote "muy afectuosamente" to Seville and Córdova, not only to the Christians but to the Moorish and Jewish aljamas and, as he was popular with them, they advanced him what sums they could.[197] The process of denationalization and fusion with the Christian community was necessarily slow, but its progress gave gratifying promise of a result, requiring only wise patience and sympathy, which would have averted incalculable misfortunes.