As one of six diplomats that represented the Polish Kingdom and King Władysław II at the Council of Constance, he was one of very few supporters of Jan Hus, and consequently strongly opposed his condemnation and subsequent execution for heresy.

During Sigismund's defeat at Kutná Hora (21 December 1421), Zawisza was taken prisoner by the Hussites and subsequently released in return for a high ransom.

In 1428, Zawisza, with his retinue as a commander of a light cavalry banner of 500 horsemen, joined the forces of Sigismund in the king's war against the Ottoman Turks.

Disheartened by the king's apparent cowardice, he allegedly refused to retreat, saying, "There is no boat big enough to lift my honour."

Among further descendants of Zawisza were Stanisław Koniecpolski, Bogusław Radziwiłł, governor of the Duchy of Prussia, and Henryk Dobrzański, the first guerrilla commander in World War II in Europe.

[5] After his death, he was praised by the Polish historian Jan Długosz, the poet and Canon of Gniezno Adam Świnka, and by King Sigismund of Luxembourg.

In Serbia, where the Golubac Fortress is located and where he is known as Zaviša Crni (Serbian Cyrillic: Завиша Црни), he was revered as a brave knight.