The inconveniences just noted, together with the continual increase in their numbers, gave point and force to a strong remonstrance addressed to Francis van Coudenberg and his Brethren by Pierre de Saulx, Prior of the Canons Regular of St. Victor, Paris, concerning the _irregularity_ of their unaccustomed manner of life. Herein the good Prior was in effect only voicing the opinion of many zealous and prudent leaders among both clergy and laity. The times were so rife in sects and societies of false mystics, and so much mischief was wrought under the guise of piety, that any form of community life outside the cloister and the three regular vows was regarded with strong suspicion and dislike. A few years later Gerard Groote, a disciple of Ruysbroeck, and Florence Radewyn, the first spiritual Director of the Venerable Thomas à Kempis, founded a lay association of _Devout Brothers and Sisters of the Common Life_, and this society also was subjected to a fierce opposition arising from the same sentiment of distrust for all religious movement outside the beaten track. Happily, the Brothers were able to weather the storm by producing irrefragable proofs of their orthodoxy, and of their entire submission to the ecclesiastical authorities. But also, by the advice and according to the desires of Gerard Groote himself, they placed themselves under the protection and guidance of a Religious Order springing from their own body, namely the Canons Regular of Windesheim, of which congregation the Venerable à Kempis was one of the earliest members as well as the brightest ornament. Prior Pierre de Saulx urged on van Coudenberg and his associates to regularise their status, silence suspicion, and escape the many inconveniences to which at present they were exposed by embracing the Rule and adopting the habit of some already established Religious Order. With edifying humility the Community of Groenendael accepted the reproof and its accompanying counsel; and applied at once to Peter Andrew, Bishop of Cambrai, for the necessary authorisation to adopt the Institute of the Canons Regular under the Rule of St. Augustin of Hippo. This permission the Ordinary granted most readily. With his own hands he clothed Francis van Coudenberg, John Ruysbroeck and their companions in the canonical habit, March 10, 1349, and the following day he appointed Dom Francis Provost,[3] and John Ruysbroeck he made Prior of the new Canonry. To van Coudenberg the other members of the Community, with one exception, professed canonical obedience, according to St. Augustin's Rule. The Bishop bestowed upon them many privileges and exemptions; while the Duke took them under his special protection and endowed them with sufficient revenues for the upkeep of a large establishment.