with the methods of Byzantine diplomacy and from the very beginning took successful actions to subvert a possible alliance between his enemies. Thus the Byzantines were forced to fight alone. The Byzantine army By 917, after a series of successful campaigns, the Byzantine Empire had stabilized its eastern borders, and the generals John Bogas and Leo Phocas were able to gather additional troops from Asia Minor to reinforce the imperial tagmata and the European thematic troops, gathering a force of some 30,000 men. This was a very large army by contemporary standards, and its goal was the elimination of the Bulgarian threat from the north. The Byzantine commanders were convinced that their strategy would be successful. Morale was raised as the soldiers vowed by the miraculous Cross to die for one another. The spirit of the army was further raised as the troops were paid in advance and a fleet commanded by Romanus Lecapenus set off to the north at the mouth of the Danube. The Byzantines had tried to pay some Pecheneg tribes to attack, but Romanus would not agree to transport them across the Danube, and instead, they attacked Bulgarian territory on their own. The Bulgarian army The size of the Bulgarian army under Simeon I of Bulgaria is unknown. Although they ruined the Byzantine negotiations, the Bulgarians were still afraid that the old allies of the Byzantines, the Pechenegs and the Hungarians, would attack them from the north, so two small armies were sent to protect the northern borders of the vast Bulgarian Empire that spread from Bosnia in the west to the Dnieper River in the east. However, Miracula Sancti Georgii points that the Bulgarian army in the battle of Achelous was allied with Hungarian and Pecheneg troops, which helped to win the victory against the Byzantine army. In addition, Bulgarian forces under Marmais were deployed near the western borders with the Serb principalities to prevent possible unrest. The battle The Byzantine army marched northwards and set its camp in the vicinity of the strong fortress of Anchialus. Leo Phocas intended to invade Moesia and meet the Pechenegs and Lecapenus's troops in Dobrudzha. Simeon swiftly concentrated his army on the heights around the fortress. On the morning of 20 August, the battle between the Bulgarians and the Byzantines began by the River Achelous near the modern village Acheloi, 8 kilometers to the north of Anchialus (modern