Answer
The Third Council of the Lateran, documented by William, stands as a momentous ecclesiastical gathering held in 1179. Convened by Pope Alexander III, this council aimed to address critical issues of the time, including the Investiture Controversy, the suppression of simony, and the enforcement of clerical discipline. Its significant resolutions contributed to shaping the medieval church and solidified the papacy's authority during a period of religious and political transformation.