Dashed left edge = started before December 820 ·
Dashed right edge = ongoing beyond December 820
Events in December 820 3
775 – 820Leo V the Armenian (775-820)Died 25 December 820, aged 45Leo V ruled as Byzantine emperor from 813, defeating a Bulgarian siege of Constantinople early in his reign. He was murdered in the Hagia Sophia on Christmas Day 820 by conspirators loyal to his former comrade-in-arms Michael the Amorian.
820Assassination of Leo V the ArmenianByzantine emperor killed during Christmas MassLeo V was ambushed and killed by supporters of Michael the Amorian inside the Hagia Sophia during Christmas matins. The conspirators disguised themselves as clergy to get close to the emperor before striking him down near the altar. Michael was crowned emperor the same day, founding the Amorian dynasty.
820Michael II the Amorian becomes Byzantine emperorAccession following the killing of Leo VMichael II was crowned Byzantine emperor on the same day his predecessor Leo V was assassinated in the Hagia Sophia. His accession began the Amorian dynasty, which would rule the Byzantine Empire for nearly five decades. He faced an immediate challenge from the revolt of Thomas the Slav the following year.