The reign of caliph Harun al-Rashid (r. 764–809) also known as Khalifa Harun Rashid marked the height of military conquests and territorial acquisition under the Abbasids caliphate, with the caliphate extending from the boundaries of India and Central Asia to Egypt and North Africa. Harun rose through the ranks as a military commander before assuming the caliphate from his murdered brother al-Hadi (r. 785–86) and served variously as governor of Ifriqiya (modern- day Tunisia), Egypt, Syria, Armenia, and Azerbaijan. His military campaigns against the Byzantines kept them at bay. Upon becoming caliph in 764, Harun established diplomatic relations with Charlemagne (r. 742–814) and the Byzantine emperor. Diplomatic and commercial ties were also established with China.
King Harun Rashid‘s reign is often referred to as the Golden Age, a period of significant cultural and literary activity during which the arts, Arabic grammar, literature, and music flourished under his patronage. Al-Rashid figures prominently in the famous literary compilation One Thousand and One Nights. Among his courtiers were the poet Abu Nuwas (d. 815), who was renowned for his wine and his love poetry, and the musician Ibrahim al-Mawsili (d. 804). Abu ’l Hasan al-Kisai (d. 805), who was tutor to al- Rashid and his sons, was the leading Arabic grammarian and Koran reciterof his day. The classical texts were translated from Greek, Syriac, and other languages into Arabic. Harun was famous for his largesse: a well-turned poem could earn the gift of a horse, a bag of gold, or even a country estate. His wife Zubaida was famous for her charities, especially for causing numerous wells to be dug on the pilgrimage route from Iraq to Medina.
Sufism (Islamic mysticism) flourished under the caliph. The famous ascetic and mystic Maruf al-Karkh (d. c.815) was among the leading expositors of Sufism in Baghdad. By contrast, Harun instituted a policy of repressing the Shiites, who were thought to challenge this rule. The latter half of Harun’s reign was
marked by political instability. The granting of semiautonomy to the governor of Ifriqiya, Ibrahim b. al-Aghlab, in 800, followed by Harun’s destruction of the all-powerful al- Barmaki family, led to a period of political and territorial decline. Harun’s decision to divide the empire between his two sons al- Amin and al-Mamun, appointing the elder al- Amin (r. 809–813) as his successor, contributed to a two-year civil war that was followed by periods of continued instability and insurrection. The reign of al-Mamun (r. 813–833), though intellectually brilliant, was marked by territorial decline and the waning of Abbasid influence.