Abstract Pedro de Ayala served as a diplomat for King Ferdinand II of Aragon and Queen Isabella I of Castile at the courts of Henry VII, King of England, and James IV, King of Scots. In July 1498, he wrote a letter, partly in cipher, to report to his king and queen on such matters as Spain's interests in international diplomacy; the characters and activities of Henry VII and James IV; the geography, economy, politics, and culture of Scotland; marriage prospects for Spanish Infantas and the English princess Margaret Tudor; and the voyages of John Cabot to North America. Here is presented for the first time a new cipher key, a complete transcription of the letter, and a translation of the full letter into English.
Jaime et al. (Mon,) studied this question.