Barbara of Celje was born most probably in 1392 as the daughter of Herman II of Celje and Countess Ana von Schaunberg. Her father was one of the most powerful feudal lords in the Hungarian-Croatian kingdom with large estates in Slovenia and Croatia. He was also a big friend of the then King Sigismund of Luxembourg, whom he even saved by helping to escape the catastrophic defeat of the Ottomans at Nicopolis in 1396. After the death of his first wife Maria Sigismund, he chose the then minor Barbara as his future wife. They married in Krapina in 1405.