ALEXANDER III. (Orlando Bandinelli), Pope from '159 to Ii8i, was a Siennese, and teacher of canon law in Bologna and author of the Stroma, or the Summa Magistri Rolandi, one of the earliest commentaries on the Decretum Gratiani and of Sentences, based on the lntroductio ad theologiam of Abelard. In '153 he became papal chancellor, and was the leader of the cardinals opposed to Frederick Barbarossa. On Sept. 7, '159, he was chosen to succeed Adrian IV., a minority of the cardinals, however, electing the cardinal priest Octavian, who assumed the name of Victor IV. 'This antipope, and his successors Paschal III. (1164-68) and Calixtus III. (1168-78), had the imperial support; but after the defeat of Legnano, Barbarossa finally (in the peace of Venice, 1177) recognized Alexander as Pope. On March 12, 1178, Alex ander returned to Rome, which he had been compelled to leave twice, from 1162 to 1165, and again in 1167. The first\period he spent in France, the latter chiefly in Gaeta, Benevento, Anagni and Venice. In March 1179 Alexander held the third Lateran synod, reckoned by the Roman Catholic Church as the nth oecumenical council; its acts embody among them the present law requiring that no one may be elected Pope without the, votes of two-thirds of the cardinals. This synod marks the summit of Alexander's power. Besides checkmating Barbarossa, he had humbled Henry II. of England in the affair of Thomas Becket, he had confirmed the right of Alphonso I. of Portugal to the crown, and even as a fugitive had enjoyed the favour and pro tection of Louis VII. of France. Nevertheless, soon after the close of the synod the Roman republic forced Alexander to leave the city, which he never re-entered; and on Sept. 29,1179, some nobles set up the antipope Innocent III. By the judicious use of money, however, Alexander got him into his power, so that he was deposed in Jan. 1180. In 1181 Alexander excommunicated William the Lion of Scotland and put the Kingdom under the interdict. The great Pope died at Civita Castellana on Aug. 3o, 1181.
See Herzog-Hauck, Realcncyklopadie, 3rd ed. i. 340-44; Wetzer and Welte, Kirchenlexikon, 2nd ed., 1481. The most elaborate biography is H. Reuter, Geschichte Alexanders III. und der Kirche seiner Zeit (2nd ed., Leipzig, 1860).