Bulgarian lands across the Danube

In the Middle Ages the Bulgarian Empire controlled vast areas to the north of the river Danube from its establishment in 681 to its fall in 1396. These lands were called by contemporary Byzantine historians "Bulgaria across the Danube". Original information for the centuries-old Bulgarian rule there is scarce as the archives of the Bulgarian rulers were destroyed and little is mentioned for this area in Byzantine or Hungarian manuscripts.

First Bulgarian Empire

After the disintegration of Great Bulgaria following Khan Kubrat's death in 668 a large group of Bulgars followed the third son of the great Khan, Asparukh who headed westwards. In 670s they settled in the area known as the "Ongal" to the north of the Danube delta. From there Asparukh's cavalry in alliance with local Slavs annually attacked the Byzantine territories in the south. In 680 the Byzantine Emperor Constantine IV lead a large army to face the Bulgars but in was defeated in the battle of Ongala and as a result the Byzantines were forced to acknowledge the formation of new country Bulgaria in the following country. The northern border of the country followed the southern slopes of the Carpathian mountains from the Iron Gates and reached the Dneper river to the east.

The Bulgarians' main rivals in the area were the Avars to the west and the Khazars to the east. The latter were a serious threat: after they crushed the resistance of Kubrat's eldest son, Bayan they marched westwards. They waged a war against Asparukh who perished in battle fighting the invaders in 700.

To protect their northern borders, the Bulgarians built several enormous ditches which ran throughout the whole length of the border from the Timok river to the Black Sea.

In 803 Krum became Khan. The new energetic ruler pointed his attention to the north-west where Bulgaria's old enemies, the Avars experience difficulties and setbacks against the Franks under Charlemagne. Between 804 and 806 the Bulgarian armies fully annihilated the Avars and destroyed their state. Krum took the eastern parts of the Avars Khanate and liberated the local Slav tribes. Bulgaria's territory extended twice from the middle Danube to the north of Budapest to the Dnester including Transylvania with its rich salt mines.

In 813 Khan Krum seized Odrin and plundered the whole Eastern Thrace. He took 50,000 captivities who were settled in "Bulgaria across the Danube".

References

* Petăr Koledarov, "Političeska geografija na srednovekovnata bălgarska dăržava", vol. 1, Sofija 1979.
* Vasilka Tăpkova-Zaimova, "Roljata i administrativnata organizacija na t. nar. 'otvăd-dunavska Bălgarija'" in "Studia Balcanica: proučvanija po slučaj vtorija meždunaroden kongres po balkanistika", Sofija 1970.
* Ian Mladjov, "Trans‐Danubian Bulgaria: Reality and Fiction", in "Byzantine Studies/Etudes Byzantines", n.s. 3, 1998 [2000] , 85–128.