The scholar pope who brought the abacus and Arabic digits back to Europe
Around the year 1000, Gerbert of Aurillac could run calculations on his abacus that left contemporaries struggling with Roman numerals far behind. He had learned from Arabic scholarship in Catalonia and Al-Andalus, taught emperors, built star-tracking spheres, and in 999 became Sylvester II, the first French pope.
Born around 946 somewhere in Aquitaine, Gerbert was placed by his parents with Benedictine monks and entered the monastery of St Gerald at Aurillac about 963. In 967 the visiting Count Borrell II of Barcelona took him south to study mathematics. Under Bishop Atto of Vich, and probably at the monastery of Ripoll, he found manuscripts that had flowed from Córdoba, whose caliph al-Hakam II owned a library of thousands of books. Tales of Mozarab bishops versed in science fired his passion for astronomy and number.
He applied the Hindu-Arabic digits to the abacus, probably leaving out zero, which appeared as an empty column. His board was split into 27 parts, with a thousand counters carved from horn by a shieldmaker in Rheims, and the device spread widely through eleventh-century Europe. He also revived the armillary sphere, using it as a classroom model of the heavens, and later fitted one with sighting tubes, advising a colleague to confirm the pole star by checking whether it stayed fixed in the tube. He spent heavily assembling a library, writing to monasteries across Europe for classical texts.
A trip to Rome in 969 brought him to Emperor Otto I, who hired him to tutor the young Otto II. He taught at the cathedral school of Rheims from 973 to 989, apart from a frustrating spell running the ruined abbey of Bobbio, and backed Hugh Capet, whose accession in 987 ended the Carolingian kings of France. His election to the see of Rheims in 991 provoked fierce opposition and was eventually undone.
Otto III, whom he also tutored, helped make him archbishop of Ravenna and then pope. Taking the name of Constantine's adviser Sylvester I, he fought simony and clerical concubinage, and graciously confirmed his old rival Arnulf at Rheims. A Roman revolt in 1001 drove pope and emperor to Ravenna; Sylvester returned after Otto died and died himself in 1003.
Source: Pope Sylvester II
