Accounts of ancestors’ deeds naturally struck home in men who lived where they had lived; who were their descendants or their descendants’ companions, and believed that when they rode, talked, prayed, or made love, their first duty was to follow the example of the valiant forebears who had once gathered together for pleasure and glory in the same surroundings. More than any other kind of narrative, family history kept alive in the lord’s entourage the desire not to degenerate, not to let those ancient virtues, borne in the blood of old and young alike, lapse.
In the second half of the twelfth century, when chivalric culture ceased to be entirely oral and practical [as distinct from literary, abstract, intellectual], ancestral history, like the chansons and the stories, was consigned to writing. The task of setting it down was always given to a technician, a churchman who was either a member of the family concerned or attached to it as a domestic chaplain or a canon of one of the collegiate churches that adjoined every chateau of any importance in northern France. This specialist was expected to put the remembered past into a grandiose and monumental form, which is why all the texts of this kind that have survived from up to the beginning of the thirteenth century are in Latin, the language of learning and of solemn ceremonies, such as funerals, and very pompous in stye, adorned with all the devices of rhetoric.
In the course of transcription, memory was not only made more definite and more ornate; it was also given added scope and depth. The writer based his text’s structure on the genealogical trees drawn up for use as evidence in ecclesiastical courts when someone wanted to dissolve a marriage on the grounds of consanguinity, and this initial framework meant that the narrative had to follow a similar pattern. In every generation we see the main thrust of the story carried forward through some lawful and prolific marriage pact: X begets Y upon Z, his wife. But the author could go back beyond the personal memories revived in the context of divorce procedures; he was able to supplement what he had seen and heard himself or learned from older men with what he read in old books and archives. Following much the same method as I am now using, he would go through ancient records in search of traces otherwise lost, and then seek to please his kinsmen and masters by working back to the origins of the family and its founding ancestor.
To play his part fully he had to remodel memory, which he was all the more at liberty to do because it was so vague. In the case of the most distant forebears, who could be traced only through a tomb, an epitaph, or a mention in some cartulary, he was quite free to attribute to them the sort of behavior his own contemporaries regarded as exemplary; to project onto these dim ghosts all the marvelous qualities prized by family ideology. This ideology also left its mark on accounts of more clearly remembered family members, for the patron who had commissioned the history wanted his father and grandfather to receive special treatment — as well as to see himself represented in a flattering light.
So compositions concerned with genealogy constitute our most useful source, not for what they tell us about what had happened in the past but for what they tell us about what was then the present, and the self-image of the great families of the period.
— Georges Duby, The Knight, the Lady, and the Priest: The Making of Modern Marriage in Medieval France, translated by Barbara Bray, pp. 228-229.