4. MARGARET ([1144/45]-1201, bur Sawtrey Abbey, Herts). Her origin and first marriage are deduced from Benedict of Peterborough who records that "filia sororis regis Scotiæ Willelmi comitissa Brittaniæ" gave birth in 1186 to "filium…Arturum"[383]. Her birth date is estimated from the Rotuli de Dominabus of 1185 which records property “villam de Wissinton” held by “Margareta comitissa…xl annorum”, adding that “comes Britannie habet filiam suam” and that she has “i filium de Humfrido de Buun qui est infra etatem”[384]. The Genealogia Comitum Richemundiæ records that "Conanus filius Alani" married "Margaretam sororem Willielmi Regis Scotie"[385]. A manuscript which narrates the descents of the founders of Lanthony Abbey records that “dominus Humfridus quartus de Bohun, comes Herefordiæ et constabularius Angliæ” married “Margaretam comitissam Britanniæ”[386]. The Annals of Burton record the death in 1201 of “Margareta mater…Constantiæ, soror Willelmi regis Scotiæ, mater Henrici de Boum comitis Herefordiæ”[387]. m firstly (1160[388]) CONAN IV "le Petit" Duke of Brittany, Earl of Richmond, son of ALAIN Earl of Richmond & his wife Berthe heiress of Brittany ([1138]-20 Feb 1171). m secondly (1171 before Easter) HUMPHREY de Bohun, son of HUMPHREY de Bohun & his wife Margaret of Hereford (-[1181]). Hereditary Constable of England.