Pope Adrian II maintains the policies of…

Zanj—the Arabic meaning "Land of the Blacks" or "Land of the Negroes"—is a name used by medieval Arab geographers to refer to both a certain portion of the coast of East Africa and its inhabitants, Bantu-speaking peoples called the Zanj.

The seaboard is also the origin of the place name "Zanzibar Arabic”.

In recent decades, a number of Basran landowners had brought several thousand Zanj) into southern Iraq to drain the salt marshes east of Basra.

The landowners subject the Zanj, who generally speak no Arabic, to heavy slave labor in the salt flats and on the sugarcane and cotton plantations of southwestern Persia, providing them with only minimal subsistence.

In September 869, 'Ali ibn Muhammad, a Persian claiming descent from 'Ali, the fourth caliph, and Fatimah, Muhammad's daughter, gains the support of several slave-work crews, which can number from five hundred to five thousand men, by pointing out the injustice of their social position and promising them freedom and wealth.

'Ali's offers become even more attractive with his subsequent adoption of a Kharijite religious stance: anyone, even an enslaved East African, could be elected caliph, and all non-Kharijites are infidels threatened by a holy war.

Zanj forces grow rapidly in size and power, absorbing the well-trained enslaved East African contingents that defect from the defeated caliphal armies, along with some disaffected local peasantry.

In October 869, they defeat a Basran force, and soon afterward a Zanj capital, al-Mukhtara, is built on an inaccessible dry spot in the salt flats, surrounded by canals.

The origins of the "Great Heathen Army" can be seen in the band of Viking warriors who attacked Paris in 845, perhaps led by the legendary Viking, Ragnar Lothbrok.

They had raided the region from 850, repeatedly sacking Rouen and various smaller towns, perhaps striking from easily defended bases in the area of their depredations.

Much of the evidence for the Army comes from the Anglo-Saxon Chronicle.

Having gained experience across Europe, the army had arrived in Britain in late 865, landing in East Anglia.

Under the command of Halfdan Ragnarsson and Ivar the Boneless, with the support of Ubbe Ragnarsson, it aims to conquer and settle in England.

Norse sagas consider the invasion a response to the death of their father, Ragnar Lodbrok, at the hands of Ælla of Northumbria in 865, but the historicity of this claim is uncertain.

The army in late 866 had conquered the Kingdom of Northumbria.

The Danish forces in East Anglia in 869 battle defenders led by King Edmund at Hoxne (Suffolk).

Edmund dies a martyr here when (according to tradition), upon his refusal to abjure Christianity and divide his kingdom with the pagan Danish leader who had defeated him in battle, his victorious foe shoots him to death with arrows and also beheads him.

An earthquake and tsunami devastate a large part of the Sanriku coast near Sendai, Japan on May 26, 869.

Bukhara-born Arabic scholar Muhammad Ibn Ismail al-Bukhari, after making a pilgrimage to Mecca as a teenager, had subsequently spent sixteen years traveling through Asia.

Having listened to Muslim authorities, gathering traditions and sayings of the prophet Muhammad, he had then compiled these in an “Al-Jami al-sahih,” which has become enormously influential.

Following al-Bukhari’s death on August 31, 870, his tomb at Samarkand becomes an important shrine for pilgrims.

Boris, Khan of Bulgaria, although baptized by Constantinopolitan Rite, approaches the pope with a proposal to establish an independent Bulgarian church with Roman rites.

Receiving no response, he turns back to Constantinople and in 870 achieves his goal of a Bulgarian archbishopric within the imperial sphere.

Emperor Basil, seeking to confirm his deposition of Photios, patriarch of Constantinople, convenes the Fourth Council of Constantinople in 869-870, which issues no new dogmatic decisions and whose principal action is to restore Ignatius by deposing Photi0s for usurping his ecclesiastical position.

Bulgaria is formally placed under the nominal ecclesiastical jurisdiction of the patriarch of Constantinople but receives an independent archbishopric.

This has significant results both for the Balkan principalities and for the Orthodox Church, as well as greatly strengthening imperial Greek influence in the south Slav world.

The council greatly contributes to the growing rift between the Eastern and Western churches.

(The Roman church will eventually recognize it as the eighth ecumenical council, but the Eastern church for the most part will deny its ecumenicity and continue to recognize only the first seven ecumenical councils.)

The Zanj rebels gain control of southern Iraq by June 870, capturing al-Ubullah, a seaport on the Persian Gulf, and cutting communications to Basra, a few miles downstream, then …

…seize Ahvaz in Khuzestan (southwestern Iran).

The Muslim caliphate’s Turkish military leaders, having murdered or deposed each of the three caliphs they have installed from 861, install al-Mu'tamid as caliph in 870.

Having emptied the imperial treasuries to maintain the army and the court, and now deriving scant income from the caliphate’s increasingly restive provinces, the Turks finally end their murderous rule within the caliphate and allow al-Mu'tamid to govern without interference.

Ya'qub ibn al-Layth al-Saffar captures the Tahirid city of Herat in 870.

His campaign in the Badghis region had led to the capture of Kharijites who will later form the Djash al-Shurat contingent in his army.

Ya'qub now turns his focus to the west and began attacks on Khorasan, Khuzestan, Kerman and Fars.

These attacks forces the Abbasid caliphate to recognize him as governor of Kerman.