Credentes or Believers, were the ordinary followers of what became known as the Cathar or Albigensian movement, a heretical sect which flourished in western Europe during the 11th, 12th and 13th centuries.
Although Catharism sprang up in Spain, the Rhineland, Flanders and Italy its main focus was in the southern region of France, particularly the area known as the Languedoc.
Although pacifist in nature, Catharism drew the condemnation of the Catholic Church which, when persuasion failed, launched successive Crusades and instigated the Inquisition to destroy it.
They believed that all human beings contained within them an element of the Divine Light trapped in bodies of Matter by "the Prince of this world", Satan (cf Gospel of John) who had created the material universe as a consequence of his rebellion against God.
Catharism held to a doctrine of reincarnation, the individual soul being born into this world of suffering again and again until it had reached the state of inner purification which meant it could return.
As with their Perfecti leaders, the Credentes underwent immense persecution at the hands of the Catholic Church and the temporal authorities of the day who invaded their regions through a crusade launched by the Pope at the time.