Two years after al-Muwaffaq had been included in al-Mu`tamid's line of succession, Ahmad ibn Tulun began to formally question the legitimacy of al-Muwaffaq's authority. al-Muwaffaq had asked for more money from Egypt to support the ongoing struggle against the Zandj and Ahmad ibn Tulun declared that Egypt was outside of al-Muwaffaq's authority. Shortly after Ahmad ibn Tulun sent a letter to al-Muwaffaq making his feelings on the matter known, al-Muwaffaq tried sending his general Musa ibn Bugha to put the Tulunids in check. The effects of the long battle against the Zandj and fear of the growing Tulunid military caused the troops under Musa's command to refuse these orders and the attack was cut short.