Numbers of Beghards joined the Brethren of the Cross, and the two sects were confounded in the rigorous persecution conducted in Germany by the inquisitor Eylard Schoneveld, who almost annihilated the flagellants.
The lay societies of the Beghards and the Beguines (for men and women respectively) date from the end of the 12th century, and soon became extremely popular both in the Low Countries and on the Rhine.
They were especially numerous in the Rhineland in the end of the 13th and during the 14th century; and they seem to have corrupted the originally orthodox communities of Beghards, for Beghards and Brethren of the Free Spirit are used henceforward as convertible terms, and the same immoralities are related of both.
This feature seemed a reflection on the mendicant orders, and the idea of a community life without vows and not in isolation from everyday life, was looked upon as something new and strange, and even as bearing affinities to the Beghards and other sects, at that time causing trouble to both Church and state.
In 1327 the opponents of the Beghards laid hold of certain propositions contained in Eckhart's works, and he was summoned before the Inquisition at Cologne.