Al-Battani

Al-Battani (in full Abu Abd Allah Muhammad ibn Jabir al-Battani; Latinized in medieval Europe as Albategnius) was one of the most accomplished astronomers of the medieval Islamic world. He was born around 858 CE in Harran, an ancient city in the Jazira region (in what is now southeastern Turkey), and died in 929 CE at Qasr al-Jiss, near Samarra in Iraq.

His family bore the epithet "al-Sabi," marking descent from the Sabians of Harran, a community known for star-lore and astral religion; his father, Jabir ibn Sinan, is reported to have been a maker of astronomical instruments. Al-Battani himself was a Muslim, as his given name Muhammad indicates, and there is no reliable evidence that he practiced the Sabian religion.

He carried out decades of careful observations, chiefly at Raqqa on the Euphrates, and is reported to have observed a solar and a lunar eclipse at Antioch in 901. His major work, the "Kitab al-Zij al-Sabi" (a zij is a handbook of astronomical tables), refined existing values for the length of the solar year and the motions of the Sun, Moon, and planets, and advanced trigonometric methods.

Centuries later the Zij was translated into Latin and read across Europe; al-Battani is cited repeatedly by Copernicus. According to the bibliographer Ibn al-Nadim, financial and tax troubles late in life drew him from Raqqa toward Baghdad, and he died on the return journey.