section_path: Caliphate/Battle of Siffin/Arbitration proceedings
section_name: Arbitration proceedings
paragraph_text: Arbitration proceedings
  
  The two arbitrators met together in Dumat al-Jandal, perhaps in February 658. There they reached the verdict that Uthman had been killed wrongfully and that Mu'awiya had the right to seek revenge. They could not agree on anything else. Rather than a judicial ruling, this was a political concession by Abu Musa, who probably hoped that Amr would later reciprocate this gesture. Ali denounced the conduct of the two arbitrators as contrary to the Quran and began organizing a second Syria campaign. Solely an initiative of Mu'awiya, there was also a second meeting in Udhruh. The negotiations there also failed, as the two arbitrators could not agree on the next caliph: Amr supported Mu'awiya, while Abu Musa nominated his son-in-law Abd Allah ibn Umar, who stood down. At its closure, Abu Musa publicly deposed both Mu'awiya and Ali and called for a council to appoint his successor per earlier agreements with Amr. When Amr took the stage, however, he deposed Ali and appointed Mu'awiya as his successor. The Kufan delegation reacted furiously to Abu Musa's concessions, and the common view is that the arbitration failed, or was inconclusive. It nevertheless strengthened the Syrians' support for Mu'awiya and weakened the position of Ali.