One of the synods or meetings of senior churchmen held at the Lateran Palace in Rome. The First in 1123 was to bring to an end the investiture contests and to specify which aspects of life should be governed by the church and which by the secular authorities. The Second was called in 1139 to clarify doctrine and to heal the schism which had been caused by the activities of the antipope Anacletus II. In 1179 the Third Council condemned simony and regularized papal elections.

The Fourth Lateran Council (1215) is known as the “Great Council” and was called by Pope Innocent III. It condemned the Albigensian heresy and clarified church doctrine on the Trinity, the Incarnation, and transubstantiation. The Fifth Council from 1512 to 1517 condemned heresy and additionally revoked the Pragmatic Sanction of Bourges by which Charles VI of France had claimed authority over the church.