Iuga Ologul was the second son of Moldovan regnant Roman Mușat and Anastasia Mushat. According to some historical sources, Iuga have reigned for a few months.^[2] According to other sources, Iuga have ruled for two years.^[3]

In historical sources, there is a confusion between Iuga Ologul and the Lithuanian prince Yuri Koriatovich (sometimes named as Jurg Coriatovici or Iurie Koriatovici) of Podolia. This confusion is due to the fact that the name Iuga is a locally adapted version of the Ruthenian name Yuri. In fact, it is assumed that Iuga Ologul was baptized in honor of this prince, since he was the son of Roman the Ist and of his first wife, the Lithuanian princes of Koriatovites origin, the rulers of Podolia.^[4]

Iuga had brothers from his father's first marriage, Michael and Stephen (who reigned with the name of Stephen the Ist before him, from 1394 to 1399), and from the second marriage two stepbrothers: Alexander (the future regnant Alexandru cel Bun) and Bogdan "jupânul" (“the boss”).^[5]

In the majority of sources it is believed that Iuga Ologul took over the leadership of Moldova even before the death of his brother, Stefan I (which is known from the rule issued by Iuga Voda on November 28, 1399, who was dead on that date);^[6] probably giving up for health reasons. It is assumed that Stefan I appointed Iuga Ologul as successor, since his children, Bogdan and Stephen (recalled only in the bead roll ( "pomelnik") of St. Nicholas Monastery, Probota Veche, founded by their father) were too young succeed the throne and the boyars had a great influence in the country's politics and could have imposed their own candidate.

Iuga Ologul was challenged from the very beginning, by his stepbrother Alexander, who at his father's death had fled together with his brother Bogdan, according to a source at Curtea de Argeș (under his protection Mircea cel Batrin, Lord of Wallachia).^[7] The documents of that time, pointed out that Mircea Voda entered to Moldova, leading the army and installed Alexandru for reigning. Iuga had been taken as hostage to Wallachia,^[8][9] where he died January 7, 1403 (when Alexandru cel Bun did not mention him “ holy dead of before") and in 1407, in the Bistrița Monastery, he was recorded as dead.

From the rule of Iuga Voda Ologul, on November 28, 1399, it also appears that he was married and had offspring ("this is my belief, Iuga voivode, and the faith of my children, and the faith of Stephen the Voivode and his children , the faith of his brothers, the belief of Olecsandro, the belief of Bogdan ... "^[10]), but the name of his wife remained unknown. His funeral probably took place in Wallachia, but until now, it is not known where he was buried. .