John of Palermo
John of Palermo was a translator of mathematical works from Arabic to Latin who lived in Palermo, Sicily. He worked in the court of Frederick II, [Holy Roman Emperor|Emperor Frederick II].
John had been introduced into the court of Frederick II through the mathematician Domenico Ispano. John is mentioned by Leonardo Fibonacci in his The [Book of Squares|Liber quadratorum] and several problems from Arab texts by Omar Khayyam were posed to Fibonacci. Some court documents mention a Johannes de Panormo who is thought to be the same person. John translated an Arab manuscript, possibly by Ibn al-Haytham, on the parabola into Latin as the De duabus lineis semper approximantibus sibi invicem et nunquam concurrentibus. John as noted as a "notarius" and there are indications that Frederick was to send him to Tunis in 1240.