The sentence of excommunication was not pronounced. Bourchard had lodged an appeal to the Pope, but for all that, Jeanne, entirely under the influence of her French counsellors, laid siege to the castle of Quesnoy. The Lord of Avesnes, so far from being in a position to fight for his fatherland, was hard pressed to defend his wife, and during two years an intermittent warfare continued between his vassals and the vassals of the Countess of Flanders. At the end of this period he seems to have been taken captive, and there is a tradition that he was at one time imprisoned at Ghent. What became of Marguerite during her husband's captivity does not appear, but certain it is that when he had obtained his release and had withdrawn to the Château de Houffalize, on the banks of the Meuse, she found means to join him, and that here she later on bore him two sons--Baldwin and Jean. The birth of these children but increased the fury of their father's enemies. Jeanne's French counsellors were well aware that unless Bourchard's marriage could be shown to be null and void, one or other of his sons would in all probability succeed to the throne, and they feared that in that case vengeance would be meted out to the men who had persecuted him. Philip Augustus too was more than ever convinced of the necessity of annulling the marriage, which guaranteed the legitimacy of his offspring, and by making Jeanne believe that she could obtain the release of her own husband at the cost of her sister's shame, prevailed on her to re-open the case at Rome, and the outcome was a fresh sentence of excommunication which set under the Church's ban not only the Lord of Avesnes himself, but his brother Guy and the friend who had given him hospitality, Thierri of Houffalize. In vain Bourchard journeyed to Rome, there to plead his cause in person. The Pope, instead of granting the dispensation he asked, imposed on him, by way of penance, a pilgrimage to Jerusalem.