The Toledan Tables were completed around 1080 by a group of Arabic astronomers at
Toledo, Spain. They had started as preexisting Arabic tables made elsewhere, and were numerically adjusted to be centered on the location of Toledo. The Tables of Toledo were partly based on the work of
al-Zarqali (known to the
West as Arzachel), an Arab mathematician, astronomer, astronomy instrument-maker, and astrologer, who lived in Toledo. The tables were produced by a team whose membership is largely unknown, with the exception of al-Zarqali. Toledo came under Christian Spanish rule in the mid-1080s, shortly after the tables were completed. A century later at Toledo, the Arabic-to-Latin translator
Gerard of Cremona (1114–1187) translated for Latin readers the
Tables of Toledo, the most accurate compilation in Europe at the time. This collection of tables was influenced heavily by the work of earlier astronomers and tables such as that of Ptolematic tables and the work of al-Battānī. What the Toledan Tables didn't derive from previous texts was their parameters for the
mean motion of celestial bodies. These parameters use
sidereal co-ordinates which is different than other tables, Ptolemy's are tropical for instance. The original version of the Arabic
Toledan Tables have been lost but there is still over one hundred versions of the Latin translation which were used for a
Greek translation of the
Toledan Tables, written in
Cyprus in the 1330s, likely by the
Greek Cypriot scholar
George Lapithes. There are a fair amount of errors in the Toledan Tables' calculations. The Toledan Tables are almost entirely a collection of copies of other tables. Because of this, the many errors and discrepancies are primarily considered to be copy errors. == Historical Uses ==