The Ancient Thracian and Roman city of Durostorum (Dorostorum) – known as Dorostol or Drastar (Drustur) during the periods of the Bulgarian Empire in the Middle Ages – is the precursor of today’s Bulgarian city of Silistra. It was originally founded as an Ancient Thracian settlement on the Lower Danube. In 29 AD, the Romans built there a fortress keeping the settlement’s Thracian name of Durostorum (or Dorostorum). After his victories wars over the Dacians north of the Danube, Roman Emperor Trajan stationed the elite Claudius’ 11th Legion – Legio XI Claudia – at Durostorum, and the fortress remained its permanent seat until the demise of the Roman Empire. In 169 AD, during the reign of Emperor Marcus Aurelius (r. 161-180 AD), Durostorum was made a Roman city – a municipium. Between the 2nd and the 4th century AD, it was a major urban and military center of the Roman Province of Moesia Inferior (later divided into Moesia Secunda and Scythia Minor), and a major Roman stronghold against the barbarian invasions. The earliest 12 Christian saints from the territory of today’s Bulgaria are Roman soldiers executed in Durostorum during the Great Persecution of Emperor Diocletian between 303 and 313 AD, including St. Dasius and St. Julius the Veteran. In 388 AD, today’s Silistra became the seat of a Christian bishopric. Roman general Flavius Aetius (391-454 AD), who is known as “the last of the Romans" for his army’s victory over the Huns in the Battle of the Catalaunian Plains in 451 AD, was born in Durostorum. During the barbarian invasions of Sarmatians, Goths, Huns, Avars, Slavs, and Bulgars the city was ransacked several times. It was rebuilt during the reign of Byzantine Emperor Justinian I the Great (r. 527-565 AD).
The Slavs settled in Durostorum around 590 AD, and named it Drastar (Drustur). The city became part of the First Bulgarian Empire (632/680 – 1018 AD) around 680 AD. Bulgarian Khan (or Kanas) Omurtag (r. 814-831 AD) is known to have built there a large imperial palace known as the Danube Palace of Bulgarian Khans where later Bulgarian Tsar Simeon I the Great (r. 893-927 AD) resided in 896-897 AD. In 895 AD (during the Bulgarian-Hungarian War of 894-896 AD), the Magyars (Hungarians), allies of Byzantium, besieged the Bulgarian army under the personal command of Tsar Simeon I the Great in the fortress of Drastar but were repulsed. The next year the Magyars were decisively defeated by the Bulgarians in the extremely fierce Battle of Southern Buh (in today’s Ukraine) which eventually led their tribes to retreat to the west and settle in the region of Pannonia essentially founding today’s Hungary.
During the later years of the First Bulgarian Empire the region around today’s Silistra was known for its rock monasteries. In 927 AD, Drastar became the seat of the first internationally recognized Patriarch of the Bulgarian Orthodox Church, Patriarch Damyan. In 969 AD, it was captured by Knyaz Sviatoslav I of Kiev, the ruler of Kievan Rus in 945-972 AD, but two years later it was conquered by Byzantium under Emperor John I Tzimiskes (r. 969-976 AD) in the Battle of Dorostolon, and renamed Theodoropolis, after military saint Theodore Stratelates. In 976 AD, Bulgaria’s Tsar Samuil (Samuel) (r. 977/997-1014 AD) regained the city until 1001 AD when it was again conquered by the Byzantine Empire.
Drastar was a metropolitan’s residence and a major fortress during the Second Bulgarian Empire (1185-1396 AD). In 1279 AD, under Tsar Ivailo (r. 1277-1280), Drastar withstood a three-month siege by the Mongols. It was conquered by the invading Ottoman Turks in 1388 AD (ca. 1400 AD, according to some sources), and turned into a major Ottoman fortress. Subsequently, Silistra has remained a major urban center in the Lower Danube region.