Ya`qub, sensing that the offer was made due to the weakness of the caliph, rejected it and wrote back that he would be advancing to the capital. The offer also alienated the Turks of Samarra, who felt that Ya`qub represented a threat to their interests. Seeing that an agreement with the Saffarid was impossible, al-Mu'tamid decided upon war and pronounced a formal curse upon Ya`qub. On March 7, 876 he left Samarra, leaving his son al-Mufawwad in charge of the capital. On March 15 he arrived at Baghdad, before arriving near Kalwadha and setting up camp. From there his army marched to Sib Bani Kuma, where al-Mu'tamid's general Masrur al-Balkhi joined him after slowing down Ya`qub's army (see below). While there the caliph gathered more troops to his side.