Danube Bulgaria was established in 681 as a union between Bulgars and Slavs who settled here a century earlier. Leadership of the new state was taken by the ruler of the proto-Bulgarians Khan Asparuh, who made Pliska his capital.

In 704 the second Bulgarian ruler, Khan Tervel, was granted the title Caesar for the military support he gave to emperor Justinian, which created precedent in history. He became famous with his brilliant victory over the Arabs at Constantinople in 718 when his army joined forces with the army of Byzantine Emperor Leo III. Constantinople and the whole European continent were thus saved from the invasion. The glory of Khan Tervel reached France, where he becomes character in the lyrical poems called chansons de geste which praise his military victories. He was called The Savior of Europe from his contemporaries and the name of Bulgaria became symbol of great military power.

The First Bulgarian Empire was at the peak of its powers in the period between 8th - 9th century. Thanks to strong and far-sighted rulers like Khan Krum (803-814), Knyaz Boris I (852-889) and Tsar Simeon I (893-927) the state expanded vastly its territory, covering todays Serbia, Republic of Macedonia, Greece, Romania and Republic of Moldova and became one of the three greatest powers in Europe, along with the Frankish Empire of Charles the Great and Byzantium.

In 864 under the reign of Knyaz Boris I Bulgaria adopted Christianity as official religion and Bulgarian Church became independent.

Knyaz Boris I had great contribution to the creation and distribution of the Bulgarian alphabet the Cyrillic alphabet by giving shelter to the disciples of Cyril and Methodius in 886.

The reign of Tsar Simeon I is called the Golden Age of the Bulgarian culture". He moves the capital to Preslav which quickly became important artistic and intellectual centre. This Bulgarian ruler was extremely well educated man and during his reign, numerous centers of enlightenment all over his kingdom were established. Bulgaria whose territory spreads from Adriatic to Aegean sea, covering present day Greece, Romania, parts from Ukraine and Hungary, Serbia, Albania and Republic of Macedonia is the biggest state in Europe at the time and biggest rival of Byzantium. Byzantine Empire saw serious threat in his expansive foreign policy well aware that after numerous successful military campaigns he will finally set his eyes on Constantinople. Unfortunately however his heirs had neither his shrewdness nor his military skills and thus the state quickly lost some of its territories, as well as its position of Great Power.

Bogomil movement came into being around 950. That dualistic heresy (they believed the world has two opposite principles: Good and Bad), was created by an orthodox priest called Bogomil, proclaiming full repudiation from earthly goods and poverty. They also refuse to acknowledge the holiness of Virgin Mary and all the Saints as well as the Holy Communion, marriage and baptism. They are also against the church as an institution, the clergy and icons, accepting only The New Testament and interpreting it in their own way. As part of their struggle they encourage poor folk into insubordination to masters and laws, criticize social inequality and wars, condemn the dissipation and prodigality of the noblemen and higher clergy. They call for modesty, pure morals and forbearance. Of course all members of the movement are persecuted. However their teachings spread through Byzantium, Russia, Northern Italy and Southern France where their successors become Cathars and Albigenses. Persecuted throughout Europe by Inquisition their cult along with their successors Cathars and Albigenses paved the way for the Reform however.

Endless wars with Byzantine empire exhausted Bulgarias strength.

Toward the end of this millennium Byzantium succeeds to capture Thracian and Moesian lands, including the capital Preslav. Tsar Samuil moves his capital to Ohrid (in todays Republic of Macedonia). In 1014 Byzantine emperor Basil II wins victory over the Bulgarian army counting fifteen thousand strong men. His troops capture about ten thousand Bulgarian soldiers. Then the byzantine emperor gives order, the remains of Bulgarian army to be divided to groups consisting of one hundred men each, where ninety nine of them should be blinded on the spot and the hundredth person left one eyed so he can lead his fellow soldiers on their way back to Ohrid. When Tsar Samuil meets his soldiers he is so deeply moved by that grim sight that he suffers heart attack and dies on the 6 of October 1014. The Byzantine Emperor Basil II is since then known as The Bulgar-Slayer.

In 1018 Bulgaria after losing series of important battles ultimately became a Byzantine province.