Battles

Entente forces on the Salonika Front repeatedly attempted to advance towards Bitola, an approach protected by Bulgarian defences around the bend of the Crna River. Serbian units made the first unsuccessful attempts to break through in the autumn of 1916.

The battle was fought between two Bulgarian divisions, the 6th Bdin and 8th Tundzha, and French forces from the Entente's Army of Salonika. The French plan called for driving the Bulgarians from their positions on Baba Mountain and then securing the Bitola and Prilep plains as a base for advancing into the Vardar Valley.

After the major Bulgarian victory at the Gates of Trajan on 17 August 986, civil war broke out in Byzantium. The empire soon also became involved in conflict with the Fatimids over Syria.

After the uprising of the brothers Asen and Peter in 1185 and the restoration of the Bulgarian state, Byzantium did everything possible to regain control of its lost territories. The late twelfth century was marked by bitter and bloody wars with the empire.

After success at Constantia, Kaloyan's army advanced towards Varna, the last Bulgarian region north of the Balkan Mountains still held by Byzantium. Mercenary garrisons defended its fortress.

The Battle of Yarebichna took place from 29 to 31 May 1918 at Yarebichna Peak, 1,097 metres high, in the Paiko Mountains, between Greek-French forces and Bulgarian troops. The 49th Infantry Regiment was completely destroyed: six hundred soldiers were killed and 1,712 captured.

In 836, Emperor Theophilos decided to violate the thirty-year peace treaty between Byzantium and Bulgaria concluded with Omurtag and launched a campaign against Bulgaria. The Bulgarians responded by entering Byzantine territory, reaching and capturing Edirne.

After the defeat of 969, Bulgaria became Kievan Rus' ally in its forthcoming war against the Byzantine Empire. During that war, in the spring of 971, Byzantium reversed the course of events and launched a major land and sea operation against the Bulgarian capital, Veliki Preslav, defended by Bulgarians and Rus'.

Following Khan Kormisosh's unsuccessful operations against Byzantium, the emperor decided to campaign against the Bulgarian state, probably then ruled by Khan Vineh. A fleet was sent towards the Danubian lands, while the emperor led the land forces into the interior of Thrace.

After the victory at the Gates of Trajan and the ensuing Byzantine civil war, the Bulgarian tsar Samuel exploited his position and began a series of attacks on Byzantine fortresses and towns in the Balkans. In 995, after successfully conquering much of the northern Balkans, he decided to turn south.

In early September 1916, only days after Romania joined the war on the Entente side, Bulgarian troops successively captured Dobrich, Tutrakan and Silistra, recovering territories taken by Romania during the Second Balkan War. The Bulgarian advance was halted on 19 September at the First Battle of Cobadin.

The Ovche Pole Operation took place from 14 October to 15 November 1915. Its aim was to prevent Serbian forces from joining the Entente troops in Thessaloniki.