The Fourth Crusade was fertile in chroniclers. Villehardouin's work was supplemented by the chronicle of Henri de Valenciennes, which is written in a somewhat similar style, but with still more resemblance to the manner and diction of the Chansons, so much so that it has been even supposed, though probably without foundation, to be a rhymed Chanson thrown into a prose form. This process is known to have been actually applied in some cases. Another historian of the expedition whose work has been preserved was Robert de Clari. Baldwin Count of Flanders, who also accompanied it, was not indeed the author but the instigator of a translation of Latin chronicles which, like the _Grandes Chroniques de France_, was continued by original work and attained, under the title of _Chronique de Baudouin d'Avesnes_, very considerable dimensions. The thirteenth century also supplies a not inconsiderable number of works dealing with the general history of France. Guillaume de Nangis wrote in the latter part of the century several historical treatises, first in Latin and then in French. An important work, entitled _La Chronique de Rains_ (Rheims), dates from the middle of the period, and, though less picturesque in subject and manner than Villehardouin, has considerable merits of style. Normandy, Flanders, and, the Crusades generally, each have groups of prose chronicles dealing with them, the most remarkable of the latter being a very early French translation of the work of William of Tyre, with additions[133]. Of the Flanders group, the already mentioned chronicle called of Baudouin d'Avesnes is the chief. It is worth mentioning again because in its case we see the way in which French was gaining ground. It exists both in Latin and in the vernacular. In other cases the Latin would be the original; but in this case it appears, though it is not positively certain, that the book was written in French, and translated for the benefit of those who might happen not to understand that language. [Sidenote: Joinville.]