Beatriz de Castilla, marchesa del Monferrato

• https://en.wikipedia.org/wiki/Beatrice_of_Castile,_Marchioness_of_M...

Beatrice of Castile (5 November or 6 December 1254 – 1286) was a daughter of Alfonso X of Castile and his wife Violant of Aragon. She was Marchioness of Montferrat by her marriage and was mother of Irene of Montferrat.

-http://fmg.ac/Projects/MedLands/CASTILE.htm#Beatrizdied1280MMonferrato

2. Infanta doña BEATRIZ de Castilla y León ([5 Nov/6 Dec] 1254-[1286]). Her origin is indicated by Pachymeres who records the second marriage of Emperor Andronikos II and "Irenen, e dynastis…quos marcesios sive marchiones appellant…neptem regis Hispaniæ"[1091]. Her parentage is also indicated by Georgius Phrantzes who records that "Irene, e Lombardia oriunda atque filia sororis regis Hispaniæ et nepti marchionis Montisferratensis…qui Thessalonicam…et Thessalorum rex fuit" was the second wife of "imperator Andronicus"[1092]. Alfonso X King of Castile "con la Reyna donna Yolant mi mugier et con mis fijas la Inffante donna Berenguella et la Inffante donna Beatriz" confirmed rights of the church of Valladolid by charter dated Sep 1255[1093]. Her first betrothal was arranged by her father to attract the support of Brandenburg for his candidacy for the throne of Germany[1094]. Although the name of the king's daughter is not specified in the source, it could only have been Beatriz as her older sister Berenguela was already betrothed at that date. The Chronica Jacobi de Aquis, dated to 1334, records that "Marchio Guliermus" married secondly "Beatricem filiam regis Anfoxi de Hispania"[1095]. The Chronicon Astense records that in 1286 "Guilielmus Marchio Montisferrati" went "in Hispania cum uxore sua Beatrice" who died there[1096].

Betrothed (1256) to JOHANN von Brandenburg, son of JOHANN I Markgraf von Brandenburg & his first wife Sophie of Denmark ([1233/42]-Tangermünde 10 Sep 1281, bur Kloster Chorin). He succeeded his father in [1266/67] as JOHANN II Markgraf von Brandenburg.

m (Murcia Aug 1271) as his third wife, GUGLIELMO VII Marchese di Monferrato, son of BONIFAZIO II Marchese di Monferrato & his wife Marguerite de Savoie (-in prison Alessandria 8 Feb 1292).