His parents were Pieter de Graeff and Jacoba Bicker , his younger brother was Johan de Graeff , the Lord of the semisouverain Lordship Zuid - Polsbroek .
Head entity: johan de graeff Q5539923 14 15 16
Tail entity: pieter de graeff Q1277245 3 4 5
Relation (head \u2192 tail): P22
Inverse relation (tail \u2192 head): P40