In recent discussion, gifts to the religious have been perceived as exercising a formative influence in the forging of some norms and customs of feudal tenure during the twelfth century. On the one hand, it has been suggested that gifts to the church assisted the clarification in the mind of lay feudal society of the concept of heritability—that is, the future enjoyment of inheritance—since donors could not alienate in perpetuity that which was not already heritable. This suggestion is extremely important in view of the different perceptions of political and legal historians concerning the development of heritability of tenures and tenant right during the twelfth century, which are seen variously to have existed as social or legal norms from varying times and from different causes. A related argument runs that, whilst the warranty clause in charters (but not warranty per se) was initially conceived within the framework of the personal relationship between lord and man, its more widespread diffusion in charters was stimulated largely through the auspices of these religious beneficiaries of gifts in frankalmoign. The introduction of warranty into charters at the instance of religious beneficiaries is thus related to their concern to secure their own perpetual rights in the land at a time of a nascent realisation of hereditary tenant right, and the religious were thus foremost in the insertion of warranty clauses in charters which they, as beneficiaries, wrote or influenced, to secure their own unbridled tenure in perpetuity.