Alumbrados

This is said to have been a group of illuminated or enlightened ones from Spain.  Adam Weishaupt may have taken the name Illuminati from the Alumbrados to use as the name of his group.

The Alumbrados taught a Gnostic form of Religion that believed that man could attain a direct knowledge of God and that formal Religions were not needed.

The Spanish Inquisition issued edicts against this group in 1568, 1574, and in 1623.

(I do not remember where I read this.  I forgot to write down the source.)