In 920, John was called upon by Charles the Simple to intervene in the succession in the Bishopric of Liège, when Charles’ candidate Hilduin turned against him and joined Duke Gilbert of Lorraine in rebellion. Charles then tried to replace him with another candidate, Richer of Prüm Abbey, but Hilduin captured Richer, and forced Richer to consecrate him as bishop. John X ordered both men to appear before him at Rome, with the result that John confirmed Richer’s appointment and excommunicated Hilduin. When in 923 Charles was later captured by Count Herbert II of Vermandois, John was the only leader who protested over Charles’ capture; he threatened Herbert with excommunication unless he restored Charles to freedom, but Herbert effectively ignored him. Contemptuous of the pope’s authority, in 925 Herbert had his five-year-old son Hugh made archbishop of Reims, an appointment which John was constrained to accept and confirm, as Herbert declared that if his son were not elected, he would carve up the bishopric and distribute the land to various supporters.