Literary genealogy in medieval Wales was a distinct and pervasive phenomenon. Due to genealogy's elegant ability to express perceptions of society in relation to space and time, writers of literary texts constantly engaged with the genealogical tradition, stimulating its reproduction and evolution. Although in its surviving contexts genealogy might often appear to be a peripheral element of texts whose primary focus lies elsewhere, the writers of these texts did not create their genealogies indiscriminately; rather, they consciously gave deference to pre-existing genealogical forms, conventions and indeed content, so as to render their genealogical exposition culturally legible to others who were immersed in the same tradition. This tradition of written, literary genealogy interacted continuously with the broad genealogical knowledge maintained by society as a whole. The more learned members of this society were ultimately the source for much of the genealogical information that entered the literary tradition, while the literary tradition itself acted to shape the mental structures that facilitated each individual's capacity for expressing social relations. Much of this process is hidden from view, but must be considered when seeking to understand the literary genealogical texts that survive.

The Welsh literary tradition of genealogy was arguably an offshoot of a wider Insular tradition originating in Ireland in the seventh century. Although this Insular tradition drew freely on literary models offered by the Bible, it was probably stimulated by the common political circumstances of the early medieval Irish, English and Britons, who, in order to express the political order of their ethnic groups, were required to present multiple kings’ pedigrees in relation to one another. From these beginnings, the tradition developed among the Britons of Wales in accordance with a unique combination of political, social and cultural factors. Chief among such factors was the relationship between perceptions of royal status and the chance events of political history. Major events that stimulated the writing of literary genealogy were the rise of the Merfynion dynasty in the ninth and tenth centuries, the emergence of two branches of the Merfynion as the foremost dynasties of Gwynedd and Deheubarth in the twelfth century, and the successive attempts by Llywelyn ab Iorwerth and his grandson Llywelyn ap Gruffudd to impose their hegemony across the remainder of native Wales in the thirteenth century.