The biographer of Louis I of Hungary,
John of Küküllő recorded that "Bogdan, the voivode of the Romanians of Maramureș, gathering the Romanians from this district, secretly passed into
Moldavia, which was subject to the
Hungarian Crown, but had been abandoned by its inhabitants because of the vicinity of the
Tatars." Moldavia had been a
defensive march of the Kingdom of Hungary. According to the earliest Moldavian chronicles,
it came into being when a Vlach lord,
Dragoș, and his people left Maramureș and settled on the banks of the
Moldova River in the late 1340s or the 1350s. Both Dragoș and his successor,
Sas, accepted Louis I's suzerainty. No contemporaneous sources mentioned the reasons of Bogdan's movement to Moldavia. According to Tudor Sălăgean, Bogdan left Maramureș because he "failed to get rid of the Hungarian hegemony". Victor Spinei writes that Dragoș's example encouraged Bogdan to cross the
Carpathian Mountains, especially because he knew that the Vlachs in Moldavia were opposed to Louis I's authority. A diploma of King Louis, issued on 20 March 1360, mentioned that the Vlachs rose up in open rebellion in Moldavia, but Dragoș of Giuleștione of the six sons of Bogdan's former opponent, Giula of Giuleștidefeated them, restoring the king's rule in Moldavia. According to a royal charter, dated to 2 February 1365, Bogdan and his (unnamed) sons had "stealthily" fled from Hungary because they wanted to seize Moldavia.
Balc, the son of Sas of Moldavia, tried to resist them, but Bogdan and his sons forced him to withdraw to Hungary. In retaliation, Louis I of Hungary confiscated Bogdan's domain in Maramureș and donated it to Balc and his brothers. Bogdan seized the province after Balc left for Hungary. Bogdan's action took place before 2 February 1365, but the exact date is debated. The earliest year, proposed by historians, is 1359; historians suggesting this date say that Bogdan took advantage of the local Vlachs' rebellion, documented by the 1360 royal diploma. Dennis Deletant writes that Bogdan invaded Moldavia around 1363. Radu Carciumaru proposes the same year; he says that Bogdan took advantage both of a conflict between Louis I of Hungary and
Charles IV, Holy Roman Emperor and of the decisive victory of the
Lithuanians over the Tatars in the
Battle of Blue Waters. Bogdan's action took place in 1364, according to Victor Spinei, and only in 1365, according to Tudor Sălăgean. ,
Rădăuţi John of Küküllő mentioned that Louis I's army often invaded Moldavia, but the "number of Vlachs inhabiting that land increased, transforming it into a country". John of Küküllő even wrote that Louis I fought most frequently against Moldavia and Serbia during his reign. However, the king's itinerary, reconstructed based on his charters, suggests that he could only take part in military actions against Moldavia in 1366, 1368 and 1370. John of Küküllő stated that the king's suzerainty had been restored in Moldavia. According to Spinei, Louis I could only force Bogdan's son,
Laţcu, to yield to him after Louis became
King of Poland in 1370. The boundaries of Moldavia during Bogdan's reign cannot exactly be determined. According to historian Laurenţiu Rădvan, his realm included the northwestern regions between the Carpathian Mountains and the Dniester River, maybe as far as the
Cheremosh River. Bogdan's seat was at
Siret where a royal residence had been built during Dragoș's reign, according to the Moldavian chronicles. He died in 1365 or 1367. He was buried in the
Saint Nicholas Monastery at
Rădăuţi. Bogdan was succeeded by his son, Laţcu. == Legacy ==