Sizzo was the son of Siger von Käfernburg but his mother is unknown. 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 two known children were Sizzo II (?-c1075) and Günther II (?-1062).
| Attribute | Date | Description | Details | Source | Multimedia | Notes |
|---|---|---|---|---|---|---|
| Nobility Title | graf von Schwarzburg |