Gerard of Cremona

There he learned Arabic, initially so that he could read Ptolemy's Almagest,[3] which had a traditionally high reputation among scholars, but which, before his departure to Castile, was not yet known in Latin translation.

Toledo, which had been a provincial capital in the Caliphate of Cordoba and remained a seat of learning, was safely available to a Catholic like Gerard, since it had been conquered from the Moors by Alfonso VI of Castile in 1085.

Toledo remained a multicultural capital, insofar as its rulers protected the large Jewish and Muslim quarters, and kept their trophy city an important centre of Arab and Hebrew culture.

Gerard of Cremona's Latin translation of the Arabic version of Ptolemy's Almagest made c. 1175 was the most widely known in Western Europe before the Renaissance.

Gerard edited for Latin readers the Tables of Toledo, the most accurate compilation of astronomical data ever seen in Europe at the time.

[citation needed] The Tables were partly the work of Al-Zarqali, known to the West as Arzachel, a mathematician and astronomer who flourished in Cordoba in the eleventh century.

Other treatises attributed to the "Second Gerard" include the Theoria or Theorica planetarum,[14] and versions of Avicenna’s Canon of Medicine— the basis of the numerous subsequent Latin editions of that well-known work — and of the Almansor of al-Razi ("Rhazes" in Latin-speaking Europe).

European depiction of the Persian physician Rhazes , in Gerard of Cremona's Recueil des traités de médecine 1250–1260. Gerard de Cremona translated numerous works by Persian and Arab scholars. [ 1 ]
Al-Razi 's Recueil des traités de médecine translated by Gerard of Cremona, second half of the 13th century.
Theorica Planetarum by Gerard of Cremona, 13th century.