Pedro de Aragón

Peter's first marriage, to Agnes of Aquitaine (betrothed 1081), was arranged by his father and performed in the capital of Jaca in January 1086. His second marriage, to a certain Bertha, probably from Lombardy, was officiated in Huesca on 16 August 1097. This represented the transferral of the capital of Aragon from Jaca to the larger city of Huesca. Peter's only children, Isabel and Peter (born c. 1086), both from his first marriage, died young in 1103 and on 1 February 1104, respectively. The boy, Peter, was wed to María Rodríguez, a daughter of El Cid, in 1098, a marriage celebrated in the Cantar de mio Cid and subsequent literature.

-https://fmg.ac/Projects/MedLands/ARAGON%20&%20CATALONIA.htm#Pedrodi...

a) Infante don PEDRO de Aragón y Navarra (-1 Feb 1104, bur 18 Aug 1104 Monastery of San Juan de la Peña). “Petrus Sancii...rex...cum filio meo Petro” donated annual revenue to “albergaria de sancta Christina de Summo portu” by charter dated Mar [1100][218]. Pedro I King of Aragon donated the church of Barbastro Santa Eulalia to “sancto Egidia de Proventia”, for the salvation of “filii mei Petri”, by charter dated Sep 1101[219]. The Crónica de San Juan de la Peña records that "los hijos del Rey" died "XV Kal Sep 1025"[220]. An epitaph at San Juan de la Peña records the burial of “Petrus infans qui...cum Isabela sorore teneris annis et ante patris mortem”[221].

[m (1098) as her first husband, MARÍA [Sol] Rodríguez, daughter of RODRIGO Díaz de Vivar "El Cid Campeador" & his wife Jimena Díaz (-[4 Aug 1104/before 1 Nov 1106]). The "Corónicas" Navarras name "dona Cristiana…dona Maria" as the two daughters of "este meo Çid" and his wife, stating that María married "el conte de Barçalona"[222]. Her supposed first marriage is indicated by the Cantar de mio cid which records the annulment of the marriages of “los infantes de Carrión” and “Ruy Díaz...mis hijas...doña Elvira y doña Sol” upon which negotiations took place for their marriages “con los de Navarra y Aragón”[223]. The date of death of her supposed first husband appears incompatible with the date of the first charter in which she appears with her [second] husband. Unless further primary source information comes to light, María´s supposed first marriage should be treated with caution. She married [secondly] as his first wife, Ramón Berenguer III Conde de Barcelona. Ramon Berenguer and his wife Maria granted property to a vassal by charter dated 1103[224]. Ramon Berenguer and his wife Maria donated property to the church of San Adrian "inmediata al rio Besós" by charter dated 4 Aug 1104[225].