The ‘Kaiserchronik’, whose first recension was compiled around the middle of the twelfth century, is the most widely transmitted and recopied work of early Middle High German literature. A text of the verse chronicle, either complete or as excerpts, is transmitted in fifty manuscripts and manuscript fragments that are still extant or known to have existed; their dates span the period from the late twelfth to the late sixteenth century, and their geographical provenance covers the entire German-speaking world, from the Upper German heartlands of the transmission through Central Germany and even (in the case of the text interpolated in manuscripts of the ‘Sächsische Weltchronik’) the Low German territories of the North. Of these fifty witnesses, twenty-seven transmit the chronicle in one or other of its two thirteenth-century verse recensions: B (ca. 1200; fifteen witnesses) and C (ca. 1250; twelve witnesses); one further manuscript contains a mixed text of A and C. These recensions make considerable changes to the old text: they recast its early MHG prosody, characterized by half-rhymes, assonances and freely rhythmicized lines of verse of up to seven or eight beats, into the new poetic norm of four-beat rhyming couplets; they abbreviate the text, and also (in the case of C) replace its prologue with a new one and extend its narrative into what for the redactor and his public was the recent past. Yet although the status of Recensions B and C as independent retextualizations is fully recognized by scholarship, a detailed and accurate appreciation of their particular tendencies and defining qualities has been impeded by the lack of an edition; researchers have been obliged to rely instead on the accounts provided by the chronicle’s nineteenth-century editors, who were more interested in the reconstruction of the original, mid-twelfth century text than they were in its thirteenth-century recensions.