Etienne de Porhoët

What is known about him is that he co-witnessed a donation charter in 1164 as brother of the donator (Eudo Duke of Brittany). He may perhaps have been a churchman, a not-uncommon occupation for younger sons.

ETIENNE . "Eudo Britannie comes" donated property to Saint-Martin de Josselin, with the consent of "fratrum meorum…Joscii vicecomitis et Alani Ceoche", witnessed by "Roaldo Dongie vicecomitis, Henrico de Arundelle, ---dio de Leon, Gaufredo de Monteforti", with the consent of "Alano de Rohan cognato meo", by charter dated 1164, witnessed by "…Stephanus frater meus…Guihomarus alterius filius de Leon…" https://fmg.ac/Projects/MedLands/brittnpr.htm#_Toc493665687