second battle of Conquereux.[382] His wife was a daughter of Theobald the Trickster,[383] and his son and successor was therefore first cousin to Odo II. of Blois; but William IV.--whom Aquitaine reckoned as her “William the Great”--seems to have had little in common with his erratic kinsman, and to have always, on the other hand, maintained a friendly understanding with Anjou. Like Odo, he once received an offer of the crown of Italy; Fulk appears in the negotiations as the friendly advocate of the duke’s interests with King Robert,[384] and though the project came to nothing, it may have been in return for Fulk’s good offices on this occasion that William bestowed on him the investiture of Saintes, a gift which was to form the pretext for more than one war between their descendants. On January 31st, 1029, William died,[385] leaving as his successor a son who bore the same name, and whose mother seems to have been a sister of Queen Constance.[386] It was this new duke of Aquitaine, known as William the Fat, whom Geoffrey Martel selected as the first victim of his heavy hand. An Angevin story attributes the origin of the war to a dispute about Saintes or Saintonge,[387] but it will not bear examination. Geoffrey Martel simply trod in the steps of Geoffrey Greygown, and with more marked success. In the autumn of 1033 he started on an expedition against the duke of Aquitaine; William encountered him on September 20th in a pitched battle near the abbey of S. Jouin-de-Marne, not far from Montcontour in Poitou; the Poitevins were defeated, partly, it seems, through treason in their own ranks, and their duke was taken prisoner.[388] For three years the duke of Aquitaine, the second great feudatary of the realm, was kept in a dungeon by the count of Vendôme;[389] not till the whole district of Saintonge[390] and several important towns were ceded to Geoffrey, and an annual tribute promised, would he release his captive. From the execution of the last humiliating condition William was delivered by death; the cruel treatment he had suffered in prison had done its work; Geoffrey had exacted the ransom for his prisoner just in time, and sent him home only to die three days after his liberation.[391] [380] _Origo Com. Vindoc._, in _Rer. Gall. Scriptt._, vol. xi. p. 31. See also Mabillon, _Ann. Bened._, vol. iv. pp. 378, 379. [381] The whole story is told only by Fulk himself, in a charter to the abbey of S. Nicolas; _Breviculum S. Nicolai_ (Le Pelletier), quoted in Mabillon, _Ann. Bened._, vol. iv. p. 379. [382] See editor’s note to Peter of Maillezais, _Rer. Gall. Scriptt._, vol. x. p. 183, note _g_. [383] Chron. S. Maxent. a. 972 (Marchegay, _Eglises_, p. 380). [384] Adem. Chabanais, _Rer. Gall. Scriptt._, vol. x. p. 161. Letters of William of Poitou, _ib._ pp. 483, 484; of Fulk to Robert, _ib._ pp. 500, 501.