The short Byzantine dynasty of 820–867, which ended iconoclasm, turned the eastern frontier in the empire's favour, and was extinguished by the murder of its last emperor.
Michael II came from Amorion in Phrygia, a garrison city in central Anatolia, and rose through the army as a companion of the emperor Leo V. In 820 he was condemned to death for conspiracy, and his supporters killed Leo in the palace chapel on Christmas morning before the sentence could be carried out.
He was brought from his cell to the throne still wearing his fetters, which nobody could find the key to. The dynasty began, in other words, in exactly the manner it would end.
He was called "the Stammerer" and was mocked by the capital's aristocracy as a provincial soldier. His reign was spent putting down the revolt of Thomas the Slav, which nearly took Constantinople, and losing Crete and much of Sicily to Muslim expansion.
Theophilos, who ruled from 829 to 842, was the most conspicuously cultured emperor of the century: he rebuilt the palace with mechanical golden birds and roaring lions in the throne room, patronised the mathematician Leo, and heard legal petitions in person on public rides through the city.
He was also the last iconoclast emperor, reviving a policy that had been dormant, and he fought the Abbasids continuously and mostly without success.
In 838 the caliph al-Mu'tasim marched on the dynasty's own home city and destroyed it. The sack of Amorion killed or enslaved most of its population and was chosen deliberately to humiliate the ruling house, and Byzantine tradition remembered the forty-two officers taken to Samarra and executed there as martyrs.
Theophilos died in 842 leaving a two-year-old son, and his widow Theodora governed as regent. In 843 she ended iconoclasm, restoring the veneration of images and holding the synod commemorated in the Orthodox calendar as the Triumph of Orthodoxy.
She managed the reversal with unusual care. Her husband had been an iconoclast and she protected his memory, insisting he had repented before death, and the settlement was made without a purge — which is a large part of why it held where the restoration of 787 had not.
She was pushed out in 856 by her brother Bardas, who governed as Caesar for the next decade while her son held the title. Her other brother, Petronas, took the eastern command.
The 860s are among the most consequential decades in Byzantine history and almost none of it is credited to the emperor whose reign it was. Petronas destroyed the army of the emir of Melitene at the Lalakaon in 863, ending the annual raiding that had defined the eastern frontier for two centuries.
In the same year Cyril and Methodius were sent to the Slavs, producing an alphabet and a liturgical language that outlasted every institution involved; in 864 the Bulgar khan Boris accepted Christianity from Constantinople; and in 860 a Rus' fleet appeared before the walls, the first appearance of a power that would matter for centuries.
The Abbasid caliphate was meanwhile collapsing into the anarchy at Samarra, which is the other half of why the eastern frontier moved. Byzantine recovery and caliphal disintegration met in this reign.
Michael III raised a Macedonian groom named Basil to co-emperor in 866, after Basil had arranged the murder of Bardas. In September 867 Basil had Michael killed in his bedchamber and took the throne, founding the dynasty that ruled for nearly two centuries.
The histories of the Amorian dynasty were then written by and for that dynasty. Michael III became "the Drunkard", a squanderer whose removal was a deliverance, and the achievements of his reign were quietly reassigned or ignored.
The distortion is unusually complete and unusually well understood, which makes this dynasty one of the clearest cases in the archive of a record written by the winners. Modern historians credit the reign with the eastern turn, the Slavonic mission and the Bulgar conversion, while noting the credit belongs largely to Theodora, Bardas, Petronas and the patriarch Photios.