From ca.

970 until 1018, a series of conflicts between the Bulgarian Empire and the Byzantine Empire leadsto the gradual conquest of Bulgaria by the Byzantines, who thus reestablished their control over the entire Balkan peninsula for the first time since the 7th-century Slavic invasions.

The struggle begins with the incorporation of eastern Bulgaria after the Rus'–Byzantine War of 970–971.

Bulgarian resistance is led by the Cometopuli brothers, who, based in the unconquered western regions of the Bulgarian Empire, lead it until its fall under Byzantine rule in 1018 and its end.

As the Byzantine-Bulgarian relations deteriorate by the end of the 960s, the Eastern Roman Empire pays the Kievan prince Sviatoslav to attack Bulgaria.

The unexpected collapse of Bulgaria and Siatoslav's ambitions to seize Constantinople catch the Eastern Roman Empire off-guard but they manage to pull back the Kievan armies and occupy eastern Bulgaria, including the capital, Preslav, in 971.

Emperor Boris II is captured and taken to Constantinople where he abdicates and the Byzantine Emperor John I Tzimiskes announces the annexation of Bulgaria, even though the Eastern Roman Empire only controls Eastern Bulgaria at this time, the lands to the west remaining under Bulgarian control.

The four brothers David, Moses, Aron and Samuel of the Cometopuli dynasty rule in the free territories and in 976 launch a major offensive against the Byzantines to regain the lost lands.

Soon the youngest brother Samuel takes the whole authority following the deaths of his three eldest brothers.Samuel proves to be a successful general, inflicting a major defeat on the Byzantine army commanded by Basil II at the Gates of Trajan and retaking northeastern Bulgaria.

His successful campaigns expand the Bulgarian borders into Thessaly and Epirus and in 998 he conquers the principality of Duklja.

In 997, Samuel is proclaimed Emperor of Bulgaria after the death of the legitimate ruler, Roman.By the end of the millennium, the fortunes of war turn in favor of the Byzantines.

The Byzantines under Basil II, a successful general and experienced soldier, slowly get the upper hand and from 1001 start to seize a number of important areas and towns.

The Bulgarians are unable to stop the annual Byzantine campaigns, which devastate the country.

In 1014, the Byzantines win the decisive battle of Kleidion and Samuel dies a few weeks later.

Tsar Samuel's reign is followed by the short reigns of his son Gavril Radomir and his nephew Ivan Vladislav.

After the death of Ivan Vladislav in 1018, there is no legitimate heir to the throne of Bulgaria and since the Eastern Roman Emperor offera very favorable terms to the Bulgarian nobility, most them choose to surrender.

All local lords who surrender are transferred either to Constantinople or to Anatolia and most of them are later assimilated into the Byzantine society.

Bulgaria loses its independence and remains subject to Byzantium for more than a century and a half, until 1185.

Its western part is transformed into one of the many Byzantine provinces, which is ruled by nominees of the Empeire.

With the collapse of the first Bulgarian state, the Bulgarian church falls under the domination of Greek ecclesiastics who take control of the see of Ohrid and attempt to replace the Bulgarian Slavic liturgy with a Greek liturgy.