The need to keep the Caliphate in the hands of the Quraish caused Caliph Haroun to put his son Al-Amin, a son of the Quraish from both sides of his family, in line for succession despite the intelligence, astuteness and wisdom of his eldest son.

Haroun Al-Rashid confirms the succession by hanging it on the Kaaba but fears for Al-Ma'moun because of the brutality of his brother Al-Amin.

Yahya Al-Barmaki's ambitions for his sons in Khorasan cause him to expand his property in the city and appoint guards to protect it; Haroun Al-Rashid married his sister Al-Abbasa to Ja'afar Al-Barmaki in name only, preventing him from contacting her.

Ibn Rabia fears Ja'afar Al-Barmaki's rise in power with the Abbasid Caliph after his marriage to Al-Abbasa, causing him to incite Al-Amin against him after discovering his plans to expand his property and his appointment of a small army.

Caliph Haroun is angry with Yahya Al-Barmaki and his son Ja'afar after Ibn Al-Rabia's success in overthrowing them, enabling him to steal a book that Yahya sent to Ibn Al-Sahl Al-Wali that was lost in Khorasan.

Caliph Haroun confiscates Yahya's property in Khorasan and gives it to his son, Al-Ma'moun. Al-Abbasa and Ja'afar violate Haround Al-Rasheed's order after she secretly meets him in his house. The Caliph declares war on the Romans.