The Constitutiones de foresta is an anonymous Latin description of forest law which purports to be authentic legislation from the reign of Cnut (1016–35). However, its details have been drawn from the author’s knowledge of twelfth-century forest administration, implicitly depicting forest law as a product of Anglo-Saxon England. The text has been informed by a broader twelfth-century consciousness of the ways in which Old English legal lexis could be employed to situate texts within specific historical circumstances. However, its author formulated a highly unusual response to this trend for the retention of key terms from vernacular legislation. As part of his attempts to replicate eleventh-century legal language, he not only included English words in his depiction of Cnut’s law, but also three words which purport to be Old Norse. This article will explore some potential reasons for his pursuit of this strategy. It argues that the dual employment of Norse and English in the Constitutiones de foresta is connected to the text’s portrayal of forest law as the legislation of Cnut, demonstrating that the inclusion of Old Norse has been inspired by the Norse terminology in the author’s main source, the Instituta Cnuti. After situating the three Old Norse terms of the Constitutiones de foresta in the wider context of twelfth-century perceptions of Norse lexis, it examines the effect of the author’s juxtaposition of Norse and English vocabulary, suggesting that his insistence on the bilingualism of Cnut’s legislation was intended to emphasize parallels with the French and English spoken in post-Conquest England. The portrayal of languages in the Constitutiones de foresta hence does not only offer evidence for post-Conquest perceptions of the relationship between Old Norse and Old English. Its self-conscious reconstruction of Cnut’s bilingual court depicts multilingualism as an index of royal magnificence: in the context both of Cnut and of the descendants of William I, linguistic plurality revealed that different peoples had been successfully united by conquest.

The text has received almost no critical attention since it was edited in the early twentieth century by Felix Liebermann, in part because of uncertainties associated with the material. The work cannot be dated precisely.