Helen of Bosnia is perhaps one of the most shadowy Queens regnant. We do not know for sure who her parents are, or when she was born. She was probably a member of the Nikolić noble family. She was born circa 1345, and she makes her first appearance as Queen consort as the wife of Dabiša, King of Bosnia on a charter dated 17 July 1392. Dabiša states in some of his charters that he had consulted with his wife, giving her some political influence. If she was from the Nikolić family, they gained significant influence during her tenure as Queen. They had at least one daughter named Stana.
In 1394 her husband designated King Sigismund of Hungary as his heir. Her husband died on 8 September 1395, though several leading noblemen refused to honour the agreement Dabiša had made with King Sigismund. Sigismund raised an army attempting to reclaim the throne. Meanwhile, the noblemen elected Helen as her husband’s successor. Sigismund withdrew upon hearing this.
Despite now being Queen regnant, Helen is considered to be no more than a puppet of the nobility. Her surviving charters all mention the involvement of the noblemen, and during her reign, they became virtually autonomous, and the internal struggles that came from this weakened the kingdom. Helen was deposed sometime between 3 April and 10 May 1398, perhaps due to the ever-growing influence of her family. Most of her family fled, but Helen remained in Bosnia where she was treated with honours due to a Queen dowager. She was succeeded by King Ostoja. Helen herself is last mentioned in a letter on 18 March 1399, and she may have died of an epidemic that plagued the area at the time.