The Chronicle of Alberic de Trois-Fontaines refers to the wife of "Aldefonsus rex Portugallie" as "filia comitis Sabaudie" but does not name her. The De Rebus Hispaniæ of Rodericus Ximenes records the marriage of "Aldefonsum" and "Mafaldam filiam Comitis Maurienæ". The Chronicon Lusitanum records the marriage in 1183 (1145) of “Rex Donnus Alfonsus” and “Donnam Matildam, Comitis Amadæi de Moriana filiam”, adding that they had three sons and three daughters. Brandaõ quotes a charter of the king dated 1146 which records “anno...quo duxeramt Mahaldam” and a charter dated Jul 1146 in which he records a donation “cum uxore mea Regina Dona Mafalda”.
It is likely that Mathilde was the daughter of Comte Amedée III's first marriage, although no proof has been found that this is correct. As she gave birth to her first child in 1147, it is improbable that she was the daughter of Comte Amedée III's marriage with Mathilde d'Albon...
She was known as dona MAFALDA in Portugal. “Alfonsus, Portugaliæ rex, comitis Henrici et reginæ Theresiæ filius, magni quoque regis Alfonsi nepos…cum uxore mea regina donna Malfada, filia comitis Amedei de Moriana” confirmed donations to La Charité-sur-Loire by his father by charter dated Jul 1145.
The Chronicon Lusitanum records the death “III Non Dec” in 1196 (1158) of “Regina D. Matilda…Comitis Amadæi filia, uxor D. Alfonsi Portugallensium Regis”. 1