The Abbasid state... its rise and fall

The Abbasid state experienced its golden age during the reigns of Harun al-Rashid and his son al-Ma'mun, as the scientific movement became active and the translation of Greek, Indian, and Pahlavi science books into Arabic flourished at the hands of the Syriacs, Persians, and Romans from the people of the Abbasid state. Muslims worked to develop these sciences and invented several useful inventions, and philosophy also flourished. Islam and the codification of the major jurisprudential schools was completed.
The Abbasid state was founded by descendants of the descendants of the youngest uncle of the Prophet of Islam, Muhammad bin Abdullah, may God bless him and grant him peace, namely Abbas bin Abdul Muttalib. In establishing their state, the Abbasids relied on the Persians who were dissatisfied with the Umayyads for excluding them from state positions and major centers, and for the Arabs to retain The Abbasids also wooed the Shiites to help destabilize the Umayyad state. The Abbasids also moved the capital of the state after the success of their revolution, from Damascus, to Kufa, then Anbar, before they built the city of Baghdad to be their capital, which flourished for three centuries, and became the largest and most beautiful city in the world, and the metropolis of science and arts, but its star began to decline with The beginning of sunset for the Abbasid Empire as a whole.