One thousand years ago, 12 May 1003, was the last time that a mathematician was pope. Gerbert of Aurillac (born in the mid-10th century, died 1003) was a monk who, after studying the trivium (grammar, logic, rhetoric) in France, studied the quadrivium (arithmetic, geometry, astronomy, music) in Spain, where he learned much from Muslim teachers. He then taught for many years at the cathedral school in Reims, where he once used the floor of the cathedral itself to set up a giant abacus. After a brilliant career as a scholar, the complex politics of the time resulted in him spending the last four years of his life as Pope Sylvester II. There are few references to his scientific writings on the web, but there is mention of a letter in which he attempts to compute an area in two different ways, and then tries to understand why his results are not the same. Britannica describes his book on the abacus as "the basic work on the subject" and mentions another volume on geometry. He is said to have introduced the use of Arabic figures into Western Europe and to have invented the pendulum clock. His great learning was regarded with superstitious dread by some, who supposed that he must have been in league with the devil. He died in Rome one millennium ago today. References Lecture notes by Prof. Lynn H. Nelson: http://www.ukans.edu/kansas/medieval/108/lectures/gerbert.html Columbia Encyclopedia: http://www.bartleby.com/65/sy/Sylvest2.html Catholic Encyclopedia (with an apparent lacuna where Gerbert's mathematical learning is described): http://www.newadvent.org/cathen/14371a.htm Mathematics and the Liberal Arts: http://math.truman.edu/~thammond/history/Gerbert.html -- Fred W. Helenius <fredh@ix.netcom.com>