Historians have interpreted Protest the conflict Violence variously ; in the words of the Iranologist Elton L. Daniel , it has been regard as `` a conflict Violence over the succession between a rather incompetent , besotted Change_sentiment al-Amin and his shrewdly competent brother al-Ma'mun ; as the product Manufacturing of harem intrigues ; as an extension Expansion of the personal rivalry Competition between the ministers al-Fadl b. Rabi ' and al-Fadl b. Sahl ; or as a struggle Violence between Arabs and Persians for the control Control of the government '' .