Babak Khorramdin in Azarbaijan suppressed. Sack of Amorium by al-Mu'tasim. Death of Abbasid prince Al-Abbas ibn al-Ma'mun. 839: Revolt of Mazyar in Tabaristan. The Muslims occupy South Italy. Capture of the city of Messina in Sicily. 842: 5 January— Death of al-Mu'tasim, accession of al-Wathiq. Death of Qaratis, mother of al-Wathiq in August 16, 842. 843: Revolts of the Arabs. Unsuccessful Byzantine attempt to reconquer the Emirate of Crete. 845: Death of the Abdallah ibn Tahir al-Khurasani Governor of Khorasan. In 845 Abbasid caliph Al-Wathiq appointed Tahir ibn Abdallah ibn Tahir as governor of Khorasan. 846: Battle of Mauropotamos between Byzantines and Abbasids in Asia Minor. 846: Hasan al-Askari, the 11th Shia Imam is born. 847: Death of Wathiq, accession of al-Mutawakkil. 850: Al-Mutawakkil restores orthodoxy. 852: Death of Abd ar-Rahman II of Spain;. accession of Muhammad I. 856: Umar ibn Abd al-Aziz al-Habbari was appointed as Governor of Sind by the Abbasid caliph Al-Mutawakkil. On 23 February 856, there was an exchange of captives with the Byzantine Empire. A second such exchange took place some four years later. 858: Al-Mutawakkil founds the town of Jafariya. 861: Assassination of the Abbasid Caliph al-Mutawakkil; accession of al-Muntasir and beginning of the "Anarchy at Samarra". Birth of famous Arab poet and prince Abdallah ibn al-Mu'tazz. 862: Abbasid conquest of Faruriyyah in Summer of 862. Al-Muntasir poisoned to death; accession of al-Musta'in. 863: The Battle of Lalakaon breaks the power of the emirate of Malatya. Start of the Byzantine counter-offensive. 864: Zaydi state established in Tabaristan by Hasan ibn Zayd (Alavids). 866: Abbasid Civil War: Al-Musta'in flees from Samarra, his deposition and accession of al-Mu'tazz; Muhammad ibn Yusuf Al-Ukhaidhir, a descendant of Ali, establishes an independent kingdom in Yamamah. 867: Ya'qub ibn al-Layth al-Saffar founds the Saffarid rule in Sistan. 868: Ali al-Hadi is poisoned. Hasan al-Askari becomes Imam. Muhammad al-Mahdi, the last Imam of shiite is born. Ahmad ibn Tulun finds the Tulunid rule in Egypt. 869: The Abbasid Caliph Mu'tazz forced to abdicate, his death and accession of al-Muhtadi. Beginning of Zanj Rebellion in Basra. 870: Turks revolt against Muhtadi, his death and accession of al-Mu'tamid. Fragmentation of Abbasid Empire into several autonomous dynasties like; Samanid, Saffarids, Tulunids, Sajid. 871: Bari is captured by Louis II of Italy, ending the Emirate of Bari. 873: Muhammad ibn Tahir, the governor of Khorasan was overthrew by rebels. 874: Hasan al-Askari is poisoned. Muhammad