In February 1117 the synod of Burgos appointed Beltrán assertor (advocate) of the exiled inhabitants of Sahagún in a lawsuit against the monks of the local monastery heard before the Archbishop of Toledo, Bernard [REF].
Beltrán's marriage, probably in 1128/9, to Elvira Pérez, illegitimate daughter of Queen Urraca and Pedro González de Lara, was arranged by the Emperor Alfonso VII [REF].