István was the son of Miklós Bánffy de Alsólendva and NN Pécz. The date and place of his birth have not been found.
His wife is not known. They were married, but the date and place have not been found. Their only known child was László (?-<1414).
| Attribute | Date | Description | Details | Source | Multimedia | Notes |
|---|---|---|---|---|---|---|
| Nobility Title | FROM 1366 TO 1372 | Varasdi ispán | ||||
| Nobility Title | FROM 1381 TO 1385 | Szlavón bán |