Constantinople, unable to effectively respond to the Bulgarian campaign due to the engagement of its forces against the Arabs, persuades the Magyars to attack Bulgaria, promising to transport them across the Danube using the imperial navy.

Leo VI may have also concluded an agreement with Arnulf to make sure that the Franks do not support Simeon against the Magyars.

In addition, the talented commander Nikephoros Phokas is called back from southern Italy to lead a separate army against Bulgaria in 895 with the mere intention to overawe the Bulgarians.

Simeon, unaware of the threat from the north, rushes to meet Phokas' forces, but the two armies do not engage in a fight.

Instead, Constantinople offers peace, informing him of both the imperial foot and maritime campaign, but intentionally does not notify him of the planned Magyar attack.

Simeon does not trust the envoy and, after sending him to prison, orders the imperial navy's route into the Danube closed off with ropes and chains, intending to hold it until he has dealt with Phokas.

Despite the problems they encounter because of the fencing, the imperial forces ultimately manage to ferry the Magyar forces led by Árpád's son Liüntika across the Danube, possibly near modern Galaţi, and assists them in pillaging the nearby Bulgarian lands.

Once notified of the surprise invasion, Simeon heads north to stop the Magyars, leaving some of his troops at the southern border to prevent a possible attack by Phokas.

Simeon's two encounters with the enemy in Northern Dobruja result in Magyar victories, forcing him to retreat to Drǎstǎr.

The Magyars had from the 940s begun repeatedly to launch pillage raids in the Bulgarian Empire.

Emperor Peter I was unable to stop them and as Constantinople is unwilling to send any help he had finally allied with the Magyars and given the save passage through Bulgaria to attack imperial Thrace.

In 968, Constantinople’s Emperor Nikephoros II Phokas pays the Kievan knyaz Sviatoslav Igorevich to attack Bulgaria in response to the alliance between the Bulgarian emperor Peter I and the Magyars.

Sviatoslav Igorevich gathers sixty thousand troops and starts his campaign in the early spring of 968.

He meets the Bulgarians, who are only thirty thousand strong, near Silistra.

The battle continues the whole day and until dark the Bulgarians seemed to have overwhelmed the Kievans, but, elated by Sviatoslav's personal example, the latter are victorious due to their still larger army.

The Bulgarians retreat to the Silistra fortress and withstand the following siege.

The Rus' forces continue their victorious campaign and though they fail to take Silistra, they seize eighty other fortresses.

Sviatoslav is eventually forced to return to Kiev after Bulgarian diplomacy inspires the Pechenegs to besiege his capital.

Boris II now becomes a captive of John I Tzimiskes, who continues to pursue the Kievan Army, besieging Sviatoslav in Drăstăr (Silistra), while claiming to act as Boris' ally and protector, and treating the Bulgarian monarch with due respect.

…Tzimiskes' forces proceed to lay siege to the northern fortress of Dorostolon, where Sviatoslav had been forced to flee.

The imperial army is reinforced by a fleet of three hundred ships equipped with Greek fire.

There are several engagements before the walls of the city, which demonstrated to the Greeks that the Rus' lack skill in cavalry warfare.

Among the casualties are the Emperor's relative, Ioannes Kourkouas (whose severed head is displayed by the Rus from one of the towers) and the second-in-command in Sviatoslav's army, a certain Ikmor (who is killed by Anemas, a son of the Cretan emir, in revenge for Ikmor's assassination of his father during the Empire’s siege of Crete).

The Rus' and their Bulgarian allies are reduced to extremities by famine.

In order to appease their gods, they drown chickens in the Danube, but the sacrifices fail to improve their position.

As their hardships become intense, two thousand Rus' warriors (including some women) sally out at night, defeat an imperial force and go in search of supplies to the Danube; they later rejoin the besieged.

The Rus' feel they cannot break the siege and after sixty days agree to sign a peace treaty with the Empire, whereby they renounce their interests towards the Bulgarian lands and the city of Chersonesos in Crimea.

Svyatoslav bitterly remarks that all his allies (Magyars, Pechenegs) had betrayed him during this decisive moment.

He is allowed to evacuate his army to Berezan Island, while the Greeks enter Dorostolon and rename it Theodoropolis, after the reigning empress Theodora.

News reaches the imperial court of a huge invasion from the north in the spring of 1087.

The invaders are Pechenegs from the northwest Black Sea region; it is reported that they number eighty thousand men in all.

Displaced by the Cumans, the Pchenegs raid into Thrace, and Alexios crosses into Moesia to retaliate but fail to take Dorostolon (Silistra).

During his retreat, the emperor is surrounded and worn down by the Pechenegs, who force him to sign a truce and to pay protection money.

The former pretender Melissenos, commanding the imperial left wing, is taken captive along with many other soldiers, to be ransomed by the emperor after some time.

Alexios, following the collapse of the rebel alliance due to intertribal disagreement about plunder, buys off the Bogomils and takes them into his army to fight the Pechenegs, the Cumans having removed to the north.

…the Cumans leave en masse for Bulgaria, pillaging as they go.

...Silistra, while ...

...Silistra, and the Turkish grand vizier enters into peace negotiations with Rumyantsev.

The Turks lose Silistra in 1829, and ...