Komnenian restoration

Previous emperors had also squandered the large gold deposits of Constantinople, so the defense of the empire had broken down, and there were few troops to fill the gaps.

In almost every year since the death of Emperor Basil II, the aristocracy rose up in revolt across the empire, east and west causing the army to move back and forth exposing their borders to raiding parties of Normans, Pechenegs or Turkic horsemen.

The empire's holdings in Southern Italy were finally lost to the Normans under Robert Guiscard and his son Bohemond of Taranto, who quickly turned to the weakly held Balkan provinces of Byzantium that were ripe for plunder.

Constantine VIII had no male heirs and as a consequence, the bureaucrats of Constantinople married his daughters Zoe and Theodora to older and incompetent men unfit for rule who were ill-advised and squandered money on trivial things.

Byzantine frontier defenses fell into decay as successive emperors disbanded the large standing armies of previous eras in order to save money.

However, the untrustworthiness, unruliness, ambitiousness, and sheer expense of these mercenary troops meant that they disrespected state authority and also conducted raiding in the Byzantine Anatolia, even sometimes working with Turkic raiders whom they were employed to fight against.

The battle of Manzikert was not immediately militarily decisive but subsequent events spiraled out of control and thus constitutes a seminal moment in Byzantine history.

Alexios did not have a strong enough army to successfully resist the invasion at first and suffered a grave defeat at the Battle of Dyrrachium (1081), which allowed Robert Guiscard and his son Bohemond to occupy much of the Balkans.

Robert was then forced to leave Greece to deal with an attack on his ally, the Pope Gregory VII, by the Holy Roman Emperor, Henry IV.

While relations between crusaders and Byzantines were not always cordial, the coordination between the two armies was instrumental in capturing many important cities in Asia Minor and eventually Jerusalem itself.

John continued Alexios' military successes and was known throughout his reign to be a kind and cautious commander who never risked Byzantine forces in huge pitched engagements that could have resulted in large catastrophes.

Nevertheless, John made steady progress throughout his reign on the Anatolian front, eventually conquering a road to Antioch so that he could keep watch over the Crusader princes who ruled it.

Due to his continuous military successes the Byzantine empire was kept safe and its realms were free from destruction and allowed to grow and prosper.

Yet John died suddenly in 1143, possibly from a poison arrow treacherously sent to him by jealous crusaders who did not want him to succeed and encroach on their territory or sovereignty.

He continued the Komnenian restoration admirably, particularly in the Balkans where he consolidated Byzantine holdings and inflicted a crushing defeat on the Kingdom of Hungary in 1167 at the Battle of Sirmium.

Indeed, of all the Byzantine emperors it is said that Manuel was the closest to healing the centuries-old rift between the Christian Churches of the East and West, though he never fully achieved this goal.

Though Andronikos worked tirelessly to root out corruption in the Empire, his heavy-handed tactics against the aristocracy naturally led to dissent, and he was eventually overthrown in 1185.

The death of Andronikos ended the century-long revival of the Komnenoi, and the Empire descended into civil war as the aristocracy and military elite grappled for control.