While Isolde's ordeal certainly represents the most dramatic of the ordeals by fire in secular German literature, it needs to be seen in the context of the legends of saintly queens who underwent similar ordeals, since there seems to have been cross-referencing and implicit comparison between legend and secular literature. Though Isolde was sexually active in both marital and extramarital contexts, the Richardis of the Kaiserchronik maintains that she has been faithful to her husband; the marriage of Heinrich and Kunigunde is portrayed in the legend as a spiritual or chaste one, though there is no historical evidence that such was the case.

Both of these accounts are relatively obscure, especially the Middle High German version of Kunigunde's life; but they contain much material of interest not only about ordeals but also about female spirituality in the medieval German lands. Since these legends involve sexual fidelity or continence in marriage, a brief introduction to the significance of this theme will help to explain the context in which the demands for the ordeal arose, since both involved accusations of adultery. While there is no such creature as a medieval attitude toward sexual relations, there are recurrent and often diverging patterns regarding doctrines in regard to sexuality in the medieval church: sex for reproduction, sex as sinful and shameful behavior, and sexual relations in marriage as a symbol expressing the partners' love for each other.