For reasons that merit study in themselves, the discipline once known as "English philology" split some decades ago into the separate fields of Old and Middle English, to the detriment of both. Never numerous to begin with, monographs traversing both periods of pre-modern English grew increasingly scarce, with the interpretative tools employed by specialists becoming ever more divergent. Recent studies focusing on the neglected intermezzo known as "Early Middle English" have begun to close this gap by inviting us to think about the artificiality of this division and consider possible continuities between pre- and post-Conquest English.  Yeager's monograph attempts something bolder still in arguing for the residue of Anglo-Saxon themes in verse of the fourteenth century.
Yeager does not argue for direct influence from Anglo-Saxon texts on the school of Langland (though sometimes, as on p. 192, it's a bit difficult to be sure). Instead, what Yeager calls "Anglo-Saxon legal-homiletic discourse" ties together such seemingly disparate materials.  The argument is not easily summarized. Earlier commentators have seen in texts of the Middle English alliterative tradition survivals of either Old English verse or rhythmic prose (as composed by Ælfric, for example). Yeager argues that the style of these texts also reveals a debt, heretofore overlooked, to the formal devices of pre-Conquest legislation. Such devices are held to derive principally from laws prepared by Wulfstan, Bishop of London and Archbishop of York (d. 1023), though inspiration may have been found even in those preserved in the twelfth-century Textus Roffensis (11).
The argument is made in six chapters. The first two, "From Written Record to Memory: A Brief History of Anglo-Saxon Legal-Homiletic Discourse" and "Leges Cnuti, Sermones Lupi: Homily, Law, and the Legacy of Wulfstan," offer rich discussions of the rhetorical strategies underlying Wulfstan's legislation and other nonliterary Anglo-Saxon texts. The most significant of these tropes for Yeager's purposes is a kind of "formally sententious language" typically employing alliteration and used to lend an authenticating force to "criticism of bureaucratic innovation" (95). (Yeager maintains that this style survives for use by later audiences even through Latin intermediaries such as the Leges Henrici Primi .) The argument crystallizes by the close of the second chapter: "In the same way that homiletic style...perform[s] an 'orality' defined by its resistance to innovations in literate secular administration, so also did the 'orality' of vernacular alliterative poetry in the thirteenth century derive from its origins in a system of education that had lost its practical purpose" (98).
Remaining chapters trace these rhetorical figures and motifs through early and late Middle English texts. In chapter three, the i>Proverbs of Alfredand First Worcester Fragment are held to "take Anglo-Saxon legal forms derived from oral precedent and leave out the legal content, to reinvent these forms as a vernacular literary mode appropriate for articulating dissatisfaction with the institutionalized literacy of the high and late medieval periods" (102-103). Similar developments are argued for in Lagaman's i>Brut (chapter 4), where the devices identified by Yeager are employed with more ambivalence (p. 148) but a similar note of nostalgia. The remaining chapters argue for the survival of this discursive tradition in the Langlandian school of verse as well as Chaucer's "repression of Anglo-Saxon legal-homiletic discourse from The Canterbury Tales" (214).
For the most part, Yeager's argument is pursued with admirable care and rigor. His book shows evidence of wide reading in the scholarship on pre- and post-Conquest English law and makes a number of valuable observations about both these texts and those in Middle English (an area in which he seems more confident). That it will have scholars working in later periods thinking about earlier English law is reason in itself to be grateful for the book, though "Anglo-Saxon legal-homiletic discourse" struck this reviewer as an increasingly elusive target the more this study grew concerned with finding its traces in later Middle English texts.
Some of the book's conclusions should be received with caution.  For example, while some features of Wulfstan's prose in particular may arguably survive in Middle English texts, the author at the very least overstates his case when he attempts to make similar use of Æthelberht's compilation of laws. The text is held by Yeager to be "part of the twelfth-century tradition of Old English literature that is the crucial link in the chain connecting Old English verse to the alliterative revival," its continuities with what is to come later evident in its being composed in a "rhythmic and sometimes alliterative" style (11). This may well be the case in some general sense. But is Æthelberht alliterative in the same way that Wulfstan's writings are? Instances of alliteration in Æthelberht's laws are sparse and its style seems only inadvertently rhythmic. For the most part, it's a series of short, clunky conditional sentences choked with hapax legomena and other obscurities, some of which are better understood now than they were in the twelfth century.
I also wonder if the author overestimates somewhat the extent to which Roffensis and other monuments to the post-Conquest study of pre-Conquest English law were actually read as the Norman Conquest faded from living memory. While there is no doubt that those learned in the law took an interest in earlier English legislation, the more widely consulted text from the twelfth century onward was the spurious Leges Edwardi Confessoris, a text receiving only brief discussion in Yeager's study. That Yeager does not deal more with an adaption of the Anglo-Saxon legal past composed even closer to the period with which he is principally concerned is likewise surprising. The Mirror of Justices attests, among other things, to just how little was known (or knowable by available means) about pre-Conquest Anglo-Saxon history in the later Middle Ages. Its failures suggest that Yeager's arguments about the survival of Anglo-Saxon rhetorical tropes, and perhaps the traditions that underlay them, may be a bit optimistic.  I would like to have known more, at the very least, about what Yeager makes of these texts.
The book displays tremendous learning. Its value consists in its offering readers an unconventional way of looking at some of the major literary texts of late medieval England that is sure to enliven teaching and scholarship. The sheer effort involved in becoming conversant in scholarship on Anglo-Saxon and Middle English literature makes this a valuable contribution to the current scholarly literature; omissions of the sort described above are probably inevitable in a study of such breadth. The author is to be commended for this heroic attempt to unite two fields that have spent most of the past century talking past one another.
1. See, e.g., remarks in Elaine Treharne, Living Through Conquest (Oxford: Oxford Univ. Press, 2012), 3-4.
2. The term receives a succinct description on p. 4: "I define Anglo-Saxon legal-homiletic discourse as a set of formal authenticating strategies originating in the Anglo-Saxon era and continuing in the record-keeping practices of post-Conquest ecclesiastical institutions."
3. Occasionally one encounters what appear to be errors of fact. Ælfric did not translate the whole of the Old English Heptateuch (p. 109 n. 33). And I am not sure what the author is referring to when he says that "the Anglo-Norman translation of the Cnut law codes is the earliest known French language legal text" (208).
4. One unfortunate omission from Yeager's study is an article that might have lent support to his argument: Angus Cameron, "Middle English in Old English Manuscripts," in Chaucer and Middle English Studies in Honour of Rossell Hope Robbins, ed. Beryl Rowland (Kent, OH: Kent State Univ. Press, 1974), 218-229.