Byzantium was one of the great empires in history, being the longest lasting one. It stretched
from the middle east and north Africa to the Italian peninsula and the Danube river.
The generally accepted and well-known timeline of the Byzantine or Eastern Roman Empire is
between 330 and 1453 AD. During its history, the Empire faced a plethora of famines,
civil wars, earthquakes, and never-ending waves of invaders, primarily from the east and the north.
Across its eastern borders in the Middle East and Anatolia, Persians, Arabs, Kartvelians, and
later Turkic tribes would invade the Empire's territories. Sometimes as raiders,
looking to extract slaves and resources, other times with the intent of conquering land and
settling there. In the northern borders of the Empire, in the Balkan peninsula,
the same pattern would repeat but with different invaders. Turkic, Slavic, Germanic and even
Celtic tribes attacked the Empire on numerous occasions spreading chaos and destruction.
Today, we will look at one of these tribes that invaded the Balkan frontier.
Raided and conquered parts of the northern Balkans and regions of the Empire and even
besieged Constantinople in 626 AD with the aid of Persians and Slavic tribes. The mighty Avars .
Firstly we have to look at the Avar people. Who were they, and what caused their invasion?
The ethnic background of the Avars is often debated. Most scholars agree that they were
of Turkic/Mongolic/Sino-Tibetan ancestry, but some believe that they partially originated
from Iranian tribes. However, recent studies defy the latter. The genetic data suggest they
mainly originate from east Asian populations. The males examined were found to be "strikingly
homogeneous". The Avars were particularly closely related to Mongolians, Oroqens, Evenks, Xibe,
Yakuts, Kazakhs, Uzbeks, Uyghurs and Buryats. The Avars were one of the two tribes that are
thought to be the primary descendants of the Rouran Khaganate, a tribal
confederation stretching from modern-day eastern Kazakhstan to Chinese Manchuria in the east.
Like many East Asian tribal confederations, the Rouran Khaganate was no exception in
its composition, as it comprised many different tribes of various origins.
In this case, the vast majority of peoples were Turkic and Mongolic tribes,
while a small number of tribes are theorized to be of sino-Tibetan and Tungusic origin.
The Khaganate was governed by the kurultai like most Turkic-Mongolic political entities
at the time. After the emerging Göktürk Khaganate conquered them, the Avars were subjected to the
Gokturks, and their migration westward began. Eventually, they reached the Pannonian Basin
in the mid-late 6th century, where they started to dominate the local European populations.
Their society had a strict hierarchy and rules. Avars did not mix with other populations and
treated them inferior, often using them as manpower for war operations or enslaving them.
At first, the Avars were not at odds with the Byzantines as they were paid a heavy ransom in
exchange for guarding the Empire against other hostile tribes like the Gepids and the Lombards.
At the dawn of the 7th century, the Avars controlled a large portion of the Balkans
and central Europe, which stretched from what today is Romania to modern-day Austria.
The Byzantine Empire faced multiple waves of attacks from the Avars
throughout the late 6th and early 7th century while also making occasional counteroffensives.
The Avars initially had little success against the Eastern Romans. However, this changed during
the Roman-Sassanid wars of 572–591 and 602–628. The Avars found the Empire in a state of weakness
since most armies and resources were engaged on the eastern front against the Sassanid Empire.
During this period, the Avars achieved most of their victories against the Romans,
conquering fortresses and towns while raiding the countryside, aided by some Slavic tribes.
During peace with the Sassanids, the advancement of the Avars would usually halt as they would
face the Byzantines at their normal strength and would suffer a lot of defeats and even push-backs
from the Byzantine counteroffensives. During the aforementioned Byzantine-Persian war
of 602-628, the Avars would advance to such an extent in the Byzantine lands that they would
threaten and, in the end, besiege the very capital of Constantinople. After capturing the cities of
Naissus and Serdica located in modern-day Serbia in 615, and destroying Justiniana and Prima in 613
and 615, respectively, the Avars arrived in Thessaloniki. In 617, Slavic tribes
were already besieging the city for the 3rd time. The Avars aided the Slavic tribes,
and despite an earthquake during the siege, the attackers were unable to capture the city.
Despite the severeness of the earthquake, the city's walls remained intact.
While a portion of the Byzantine fleet was resupplying the city via the sea, the siege ended
in a stalemate where the Byzantines agreed to pay off the besiegers with gold and other resources.
After the siege, the Avars raided the terrestrial parts of the Empire for a few more years
while the slavs plundered the Islands of the Aegean and the coast of Asia Minor.
Before we talk about the siege itself, we need to look at the other front of the Byzantine Empire,
the east. There the Byzantines faced the Persians in a never-ending series of wars
that dated back to the times of the old unified Roman Empire.
The wars with the Persians drained a considerable amount of resources and manpower while bringing
barely any profit or territorial gains to the Empire. It was always a stalemate,
with one side gaining the upper hand for a short period only to be pushed back and
lose whatever it had previously acquired by the other. Neither Empire managed to inflict
a decisive blow against the other in all these centuries, thus gaining complete dominance.
The Sassanids were already at war with the Byzantines long before the siege of
Constantinople in 626 AD. The situation was looking grim for the Byzantines.
The Persians had captured, up until that time, the Middle East,
Egypt, the Caucasus and half of Asia Minor from the Byzantines. In 622,
only after a peace agreement was brokered with the Avars in unfavourable terms for the Byzantines due
to them being at a disadvantage, they managed to mount an effective counteroffensive against
the Sassanids and recapture Asia Minor after defeating a series of armies.
During this time, the Emperor of the Byzantium was Heraclius , and he was determined to restore
the Empire's prestige. The loss of the Holy Land was a significant blow to both his own
and his Empire's reputation. Since the Persians were now on the losing side,
they sought allies in the west to help them shift the tide of the war.
Accordingly, they agreed with the Avars and some Slavic tribes to besiege Constantinople together.
During the siege, Heraclius' army was in Pontus, Trabzon.
As a result, the first Persian army crossed Anatolia from the south without clashing
with Herclius' forces. In contrast, the second army remained at the border of Asia Minor
in order to protect the Persian heartland from a byzantine offensive.
The Persians reached Constantinople with ease and began the siege with their allies
on the 29th of June 626. The Persians besieged the city from its Asian side,
while the Avars and the Slavs besieged it from the European side. The Bosporus strait
remained under Byzantine control as neither the Persian nor the Slavic navy could match
their Byzantine counterpart. The Avars had no navy, so they could not help.
It was a significant problem for the attackers. It made communication between their forces slower
and more challenging while preventing the Persians from assisting their allies
as they were very experienced and effective in siege warfare. The combined forces of Avars and
Slavic tribes numbered about 80.000 strong while the Persians stood at 50.000, thus outnumbering
the Byzantines almost 10 to 1 as the latter had at most 15.000 troops defending their capital.
The city's defence was led by Ecumenical Patriarch Sergius and General Bonus, a very close associate
of the Emperor. They planned the defences well and prepared for a siege but remained
confident that they would not fall, deeming the enemy incapable of conquering the city.
Indeed all attacks on the city's walls and attempts to transfer troops from one side
of the city to the other were countered by the defenders. The combined force of Avars and Slavs
launched the most significant attack on the 6th of August. Still, it failed as the Byzantine heavy
cavalry stood firm and defended the city. Meanwhile, despite not being in his Empire's
capital, Emperor Heraclius did not remain inactive. Instead, he divided his army into
three smaller forces and devised a plan to end the siege. He sent the first army to reinforce
the capital's garrison while commanding the second army to harass and attack the Persian
army besieging Constantinople and its supply lines. Finally, the third army under his command
was to march to the interior of the Persian Empire and start raiding and pillaging.
The operation was a complete success as the Persian army near Constantinople was defeated
and hastily retreated. Consequently, the Slavic tribes and Avars followed suit by withdrawing
after learning about the fate of their allies. In the next few years, the Byzantines managed
to overturn the course of the war completely and gave the Sassanids a tough time on the battlefield
while even coordinating a mutual attack with the Turks , who invaded from the Caucasus.
In 628, the war ended after the Shah, Khosrow II, was overthrown and replaced by his son Kavadh II.
Heraclius secured very favourable terms of peace with the new Shah.
The Byzantine Empire was to receive hefty tribute and all the lands it had lost in
the war alongside any prisoners of war and holy relics the Persians had captured.
However, both the Persians and the Byzantines suffered significant losses from this lengthy war.
Despite the latter winning the war, both empires had lost in reality.
The constant fighting weakened them and paved the way for a new emerging empire to dominate
the region, the Rashidun Caliphate. The Arabs conquered large swaths of land
from the Byzantines. They ultimately defeated the Sassanids in 654, thus ending the Empire
and initiating the Islamization process of the previously Zoroastrian Iranian peoples.
A new era had dawned for humanity that would cause dramatic changes to all aspects of history.