[citation needed] The nickname "the Crippled" can be found only in the chronicle of Putna Monastery, drafted in the first years of the 16th century, but its origins are unknown.
[citation needed] The reasons why he has remained in history with this nickname are not known precisely (probably suffered from a disease that makes it difficult to move).
[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.
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).