invaded numerous times in turn by different tribes: Goths, Huns, Avars, Bulgars, Magyars, Pechenegs, Cumans and Mongols. The territory of Bessarabia was encompassed in dozens of ephemeral kingdoms which were disbanded when another wave of migrants arrived. Those centuries were characterized by a terrible state of insecurity and mass movement of these tribes. The period was later known as the Dark Ages of Europe, or age of migrations. In 561, the Avars captured Bessarabia and executed the local ruler Mesamer. Following the Avars, Slavs arrived in the region and established settlements. Then, in 582, Onogur Bulgars settled in southeastern Bessarabia and northern Dobruja, from which they moved to Moesia Inferior (allegedly under pressure from the Khazars), and formed the nascent region of Bulgaria. With the rise of the Khazars' state in the east, the invasions began to diminish and it was possible to create larger states. According to some opinions, the southern part of Bessarabia remained under the influence of the First Bulgarian Empire until the end of the 9th century. Between the 8th and 10th centuries, the southern part of Bessarabia was inhabited by people from the Balkan-Danubian culture (the culture of the First Bulgarian Empire). Between the 9th and 13th centuries, Bessarabia is mentioned in Slav chronicles as part of Bolohoveni (north) and Brodnici (south) voivodeships, believed to be Vlach principalities of the early Middle Ages. The last large-scale invasions were those of the Mongols of 1241, 1290, and 1343. Sehr al-Jedid (near Orhei), an important settlement of the Golden Horde, dates from this period. They led to a retreat of a big part of the population to the mountainous areas in Eastern Carpathians and to Transylvania. The population east of Prut became especially low at the time of the Tatar invasions. In the Late Middle Age, chronicles mention a Tigheci "republic", predating the establishment of the Principality of Moldavia, situated near the modern town of Cahul in the southwest of Bessarabia, preserving its autonomy even during the later Principality even into the 18th century. Genovese merchants rebuilt or established a number of forts along the Dniester (notably Moncastro) and Danube (including Kyliya/Chilia-Licostomo). Principality of Moldavia After the 1360s the region was gradually included in the principality of Moldavia, which by 1392 established control over the fortresses of Akkerman and Chilia, its eastern border becoming the River Dniester. Based on the name of the region, some authors consider