Research Notes:

The Chronicle of Alberic de Trois-Fontaines names "Constantiam comitis Conani filia" as wife of "Gaufridus dux Britannie comes Richemontis filius Henrici regis Anglie natu tertius", specifying that she married [thirdly] "Guido frater vicecomitem de Tuart". She is named by Matthew of Paris, who also gives her parentage, when he records her betrothal.

She succeeded her father in 1171 as CONSTANCE Dss de Bretagne. Robert of Torigny records the marriage in 1182 of "Gaufredus dux Britanniæ filius regis Henrici" and "filiam Conani comitis Britanniæ". The Annales Cestrienses record in 1188 that “Rannulphus comes Cestrie” was knighted “in die circumcisionis domini apud [Cadomum]” by King Henry II who also granted him “relictam [Galfridi filii sui]...comitissam Britannie filia Alani comitis Britannie...Constancia et toto comittatu de Richemund” whom he married “in die Sancte Werburge...III Non Feb apud ---“. The Genealogia Comitum Richemundiæ records that "Constantia filia Conani" married secondly "Ranulphus Comes Cestriæ", stating that he divorced her because of her adultery and that the marriage was childless. Living apart from her second husband, he captured her at Pontorson in 1196 and imprisoned her at his castle at Beuvron. She was liberated in Summer 1198, and repudiated her marriage. The Genealogia Comitum Richemundiæ records that "Constantia filia Conani" married thirdly "Guidoni de Thoarcio".

The Annals of Burton record the death in 1201 of “Constantia mater Arthuri comitis Britanniæ”. The Genealogia Comitum Richemundiæ records the death in 1201 of "Constantia filia Conani" and her burial "apud Begar". The Chronicon Britannicum records the death "III Non Sep" in 1201 of "Constantia Ducissa Britanniæ". Another Chronicon Britannicum records the death "pridie non Sep" in 1201 of "Constantia comitissa, Conani filia, mater Arturi". The Chronicon Ruyensis Cœnobii records the death in 1201 of "Constantia Comitissa apud Nannetum". ¹