Simeon I of Bulgaria

Simeon I, called the Great, ruled the First Bulgarian Empire from 893 to 927 and spent most of his reign at war with Byzantium, the empire whose capital had educated him. Under him Bulgaria reached its greatest extent, stretching between the Black Sea, the Aegean and the Adriatic, and Preslav became the centre of a flowering of Slavonic literature in which the Cyrillic alphabet took shape. He was the first Bulgarian ruler to call himself tsar, or emperor.

Simeon was born in 864 or 865, the third son of Knyaz Boris I, who converted Bulgaria to Christianity. Intended for the church, he was sent as a teenager to Constantinople, where he spent about a decade, studied rhetoric and philosophy and learned Greek so well that Byzantine writers called him "half-Greek". Around 888 he returned to a monastery at Preslav to translate religious texts into Slavonic. Boris had meanwhile handed power to his eldest son, Vladimir, who tried to revive paganism. In 893 Boris deposed and blinded Vladimir and installed Simeon instead; the same assembly moved the capital from Pliska to Preslav and made the Slavonic language official in church and state.

Simeon soon quarrelled with the emperor Leo VI, who had moved the market for Bulgarian goods to Thessaloniki and taxed it heavily. In 895 the Byzantines ferried Magyar raiders across the Danube, and Simeon lost two battles to them. He answered by allying with the Pechenegs, and in 896 their combined attack drove the Magyars out of their homeland north of the Black Sea towards the Pannonian plain. The same year he crushed a Byzantine army at Bulgarophygon in Thrace. The resulting peace obliged Byzantium to pay an annual tribute, and a further treaty in 904 gave Bulgaria most of the Slav-inhabited lands of today's Macedonia and Albania.

When Leo VI died in 912 and his brother Alexander refused the tribute, Simeon marched on Constantinople in 913. The regency under Patriarch Nicholas Mystikos paid the arrears, promised that the young Constantine VII would marry Simeon's daughter and recognised Simeon as emperor of the Bulgarians. The empress Zoe overturned these terms when she seized power in 914, and Simeon took Adrianople.

On 20 August 917 Simeon's army surprised and routed a large invading Byzantine army by the River Achelous near Anchialos, one of the biggest battles of the Middle Ages, and defeated another force near Constantinople soon afterwards. When the admiral Romanos Lekapenos made himself co-emperor in 920, ending Simeon's hopes of controlling Byzantium through marriage, Bulgarian armies raided as far as the Isthmus of Corinth and the Dardanelles. Simeon sought a naval alliance with the Fatimid caliph, but the Byzantines intercepted the envoys. In 924 he met Romanos outside Constantinople and agreed a truce. He also deposed a series of rulers in Serbia before annexing it outright in 924.

Around 925 Simeon raised the Bulgarian church to a patriarchate, and Pope John X is said to have recognised his imperial title. In 926 his army invading Croatia was destroyed by King Tomislav. Simeon died of heart failure at Preslav on 27 May 927 while preparing another war. His son Peter I made peace in 927, gaining Byzantine recognition of his imperial title and of the patriarchate.

Simeon's reign is remembered in Bulgaria as a golden age. Disciples of Cyril and Methodius, among them Clement of Ohrid and Naum, worked in the schools of Preslav and Ohrid, translating scripture, church fathers and chronicles and producing original works. Simeon built Preslav into an imperial capital with a palace, the Golden Church and more than twenty other churches.

Our 900 map shows Bulgaria at the height of Simeon's power, pressing on the Byzantine Empire from the Danube to the Adriatic hinterland.