Phokas was defeated once more at Katasyrtai where the last Byzantine troops were routed after a night fight. The way to Constantinople was clear. The Byzantines proposed a new peace treaty, and Simeon entered the imperial city and was crowned for a second time as "Tsar" (the Slavonic title for Caesar i.e. Emperor) "of all Bulgarians and Romans". Simeon also demanded that his daughter would marry Constantine VII, the son of empress Zoe Karvounopsina, but Zoe refused and allied with Serbia and Hungary against him. However, in August 918, general Romanus Lecapenus engineered a coup to depose Zoe and confined her to the monastery of St Euphemia-in-Petrium, allowing him to assume the purple. The alliance with the Serbs postponed the decisive assault of Constantinople. Due to his also heavy casualties, Simeon decided to secure his rear and sent an army from his remaining forces under Marmais and Theodore Sigritsa to destroy them. His generals captured the Serb prince but that gave the Byzantines precious time to recover due to his already diminished forces, making him have no sufficient forces to fight on both sides at the same time. Significance The battle of Achelous was one of the most important battles in the long Byzantine–Bulgarian Wars. It secured the concession of the Imperial title to the Bulgarian rulers, and thereby firmly established Bulgaria's role as a key player in Europe. However, the dynastic marriage that Simeon desired to establish with the Byzantine imperial family was foiled. After his death in 927, however, his successor Peter I was able to secure the hand of Maria Lecapene, the granddaughter of emperor Romanus I, and with it an annual tribute, the renewed recognition of his imperial title and the autocephaly of the Bulgarian church. This agreement ushered an unprecedented period of 40 years of peaceful relations between the two powers, a time of stability and prosperity for Bulgaria. Footnotes Sources Атанас Пейчев и колектив, 1300 години на стража, Военно издателство, София 1984. Васил Н. Златарски, История на българската държава през средните векове, Част I, II изд., Наука и изкуство, София 1970. John Skylitzes, Synopsis Historion, translated by Paul Stephenson. Theophanes Continuatus, ed. Bekker, pp. 388–390. Йордан Андреев, Милчо Лалков, Българските ханове и царе, Велико Търново, 1996. 910s conflicts 10th century in Bulgaria 910s in the Byzantine Empire Battles involving the First Bulgarian Empire Battles of the Byzantine–Bulgarian Wars in Thrace 917 Pomorie Battles of