The story of the Sacrifice of Isaac appears frequently in Romanesque art. Examples can be seen on interior capitals at Autun, Conques and St Sernin de Toulouse and at the cloister of Moissac. It is also featured on the trumeau at Souillac.
This theme held a particular significance for the Christians of northern Spain during the time of the Reconquista. One of the earliest representations is at the Mozarabic church of San Pedro de la Nave. During the Romanesque period it was used most notably at Jaca and is the subject of the hemicycle above the Puerta del Corderon at León, a unique use of an Old Testament subject for a tympanum.
At the cathedral of San Pedro at Jaca the capital on the right side of the entrance to the south transept entrance is of Isaac and Abraham. Here it stands opposite the capital on the left side of the entrance of Balaam and the Ass.
Isaac was considered a precursor of Christ, not least because his birth was announced to his parents Sara and Abraham by an angel and the celebrated story of the Sacrifice of Isaac which is told in Genesis 22. Abraham has two sons. Ishmael whom he had with his servant Hagar, believing his wife Sara to be barren and then Isaac when he is told by an angel that he can have a child with Sara.
In order to test Abraham’s faith God commands him to sacrifice his son and directs him to the land of Moriah. Along the journey, Isaac innocent of the intention of his father asks where the sacrificial lamb will be found. At the last moment, when Abraham has proved his willingness to carry out God’s demand he is granted a reprieve and a ram appears tangled in a thicket to be sacrificed in Isaac’s place.
The full significance of this theme for the Christians of northern Spain is borne out in the tympanum of the Door of the Lamb at the palatine basilica of San Isidoro de León. Here the central image is Abraham grasping Isaac by the hair poised with a blade over his son.
Below to the right is Sara at the door of her tent and Ishmael on his way to Moriah. This is opposed on the left side by Hagar and Ishmael. Ishmael is represented as a mounted archer clearly intended to be identified as a Saracen cavalry fighter.
God’s Covenant with Abraham was cemented by this episode and as Genesis tells us that his “seed shall possess the gates of his enemies”. This was understood to mean the line of Isaac who as a prefiguration of Christ identified the Christians as God’s Chosen and the descendants of Ishmael were the Saracens who contemporary chronicles referred to as Ishmaelites. At the time the sculpture was created at León, in the early twelfth century the northern Christians of Spain had been suffering serious setbacks in their Crusade against the Moors. The story of the Sacrifice of Isaac was seen as a prophecy of Christian victory.