Maurice's Balkan campaigns

Maurice was the only East Roman emperor, other than Anastasius I, who did his best to implement determined Balkan policies during Late Antiquity by paying adequate attention to the safety of the northern frontier against barbarian incursions.

[3] Although he rebuilt the fortifications of the Danube Limes, he avoided campaigns against the Slavs, in favour of a policy focusing on the eastern and western theatres.

[4] To make matters worse, Justin II started the Roman-Persian War of 572–591, which tied down forces in the east while they were needed in the Balkans.

A few months before Maurice's accession in the winter of 581/2, the Avar Khagan Bayan, aided by Slavic auxiliary troops, took Sirmium, a large fortified settlement south of the Danube.

[5] The Avars quickly moved east and captured Viminacium and Augustae, and they began attacking as far southeast as Anchialus after only three months of war.

[5] However, the Slavs were unhindered by the treaty and began to raid further south into Greece, as is evidenced by many coin hoards in the region, particularly in Attica near Athens and in the Peloponnese.

Despite the Roman garrison at Singidunum, the Avars destroyed the fortified towns of Ratiaria and Oescus, on the Danube, and besieged Thessaloniki in 586,[9] which were accompanied by Slavic raids down to the Peloponnese.

Under the leadership of Comentiolus, the outnumbered Roman Army avoided any direct confrontation and restricted itself to disturbing the Avar raids by skirmishes and night attacks, a tactical expedient that was advised by Maurice's Strategikon.

At Tomis, on the shores of the Black Sea, the Khagan escaped via the lagoon-shaped coast, but an ambush on the south slope of the Balkan Mountains was thwarted by miscommunication among the Roman troops: The following year, Priscus took over command from Comentiolus.

In the late summer of 591, Maurice finally made peace with Persian Shah Khosrau II, who ceded most part of Armenia to the Roman Empire.

Maurice had already visited Anchialos and other cities in Thrace personally in 590 to oversee their reconstruction and to boost the morale of his troops and the local population.

He routed them several times before he crossed the Danube to carry on the fight in the uncharted swamps and forests of modern-day Muntenia, Romania until autumn.

Then, he disobeyed Maurice's order to spend the winter on the northern Danube bank, among the frozen swamps and rivers and the leafless forests.

Despite initially failing, Peter maintained his position, defeated the Slavs (Priscus speaks about Bulgars) at Marcianopolis and patrolled the Danube between Novae (modern Svishtov) and the Black Sea.

In late August, he crossed the Danube near Securisca west of Novae and fought his way to the Helibacia River, effectively disturbing Slav preparations for new pillaging campaigns.

[13] That success enabled Priscus, who had meanwhile been entrusted with the command of another army upstream to prevent an Avar siege of Singidunum in 595 in a combined action with the Roman Danube fleet.

The fact that the Avars retreated and gave up their plans to destroy the city and deport its inhabitants, as opposed to their conquest of 584, showed their lack of confidence and the threat they saw in the border fortress.

On 30 March 598, however, they lifted the siege, as Comentiolus had led an army of rather inexperienced soldiers over the Haemimons and was moving along the Danube up to Zikidiba, near modern-day Medgidia, just 30 kilometres (19 mi) from Tomis.

[17] Comentiolus was temporarily relieved of his command and replaced by Philippicus,[18] and Maurice summoned the Circus factions and his own bodyguards to defend the long walls west of Constantinople.

However, when Maurice ordered the army to spend the winter of 602/603 on the northern bank of the Danube to further his success and to save money on quarters, his troops mutinied, as they had done in 593.

[26] That finally led to the decline of classical Roman rule in the Balkan interior, marking the end of Late Antiquity in that region.

There is no archaeological evidence such as coin hoards or destruction of communities implying Slav or Avar incursions, let alone a total collapse of Roman power during Phocas' reign.

[30] However, even so, it was Phocas' inaction, more or less imposed by the deteriorating situation on the Persian front, that paved the way for the massive invasions of Heraclius' first decade as well as the eventual collapse of Roman rule over the Balkans [33] until the campaigns of the Macedonian Emperors in the late 10th century.

Many Danube tributaries accessible by ship, Roman settlements survived like modern-day Veliko Tarnovo on the Yantra River, which even has a church built in the 7th century.

[36] Heraclius made use of the short time between the end of the last war against Persia in 628 and the outbreak of Arab attacks in 634, in order to try to re-establish at least some sort of Roman authority over the Balkans.

[37] The cities of the Balkans, traditionally the major centres of Roman civilization, had degenerated from the populous, wealthy and self-sufficient polis of Antiquity to a limited, fortified kastron.

[36] In Dalmatia, Romance languages (Dalmatian) persisted into the late 19th century, and in Macedonia, the ancestors of modern-day Aromanians survived as transhumant nomads.

[citation needed] In Albania, parts of Montenegro, Kosovo and Macedonia, a small ethnic group, unnoticed over centuries of Roman rule, retained its pre-Roman language and also survived Slavic landfall, the ancestors of modern-day Albanians.

[39][citation needed] In short, the decline of Roman power on the Balkans was a slow affair that took place only because of the lack of Byzantine military presence.

Byzantium, however, used any opportunity given by pauses of activity on the Arab front to subjugate the Slavs and resettle them en masse to Asia Minor.