WILLIAM IS MOST commonly thought of as a national historian, and it is upon his achievement in writing the history of England from Bede until his own day that his reputation has always rested. But he had wider historical perspectives, and they are important. Even in the Gesta Regum there are lengthy asides upon the histories of the Carolingian Empire, of France and Normandy, of papal-imperial relations and the crusading movement. He was also fascinated by the civilization of Antiquity, and Bodl. Libr. MS Arch. Seld. B. 16 contains his collection of chronicles of imperial history from the earliest days of Rome until the reign of Louis the Pious. To these interests and the works which they produced can be added the history of the papacy, illustrated by a unique edition of the Liber Pontificalis which William compiled. To state this is to credit him with the production of another major historical work, of similar scale to the Gesta, although formally more primitive. It is also to credit him with a major piece of research and writing which predates at least the final drafting of the Gesta Regum and Gesta Pontificum.

In 1910 Wilhelm Levison, with his customary learning and precision, described and discussed a hitherto unnoticed version of the Liber Pontificalis which had been compiled in England soon after 1119. It is transmitted in two manuscripts. As found in the first, CUL Kk. 4. 6, ff. 224–80 (C), dating from the 1130s, this version consists of three main sections, each interpolated from a variety of sources. To 715 the basis was a Class 2 manuscript of the Liber Pontificalis, perhaps a twin of B1, the incomplete late seventh-century copy from Bobbio. From 715 until 772 (plus an isolated reference c.795) the main source was a Class E manuscript of the Liber. From 741 until 1087 the compiler used a (probably Italian) Papstkatalog of a familiar type. After that he apparently made up his own brief biographies, concluding with the Acts of Calixtus II's Council of Reims, 1119. The second manuscript is BL Harl. 633 of the late twelfth century, in which the Liber Pontificalis occupies ff. 4–71 (L).