Bernhard's paternal grandparents were Margrave Engelbert III of Istria and Matilda of Sulzbach.
The known siblings of Gertrude include (1) Gebhard III, Count of Sulzbach, (2) Adelheid, Abbess of Niedernburg at Passau, (3) Bertha of Sulzbach, Byzantine Empress, (4) Luitgarde, wife first of Godfrey II of Leuven and secondly of Hugo XII, Count of Dagsburg and Metz, and (5) Matilda of Sulzbach, wife of Engelbert III of Istria.
Matilda | Sulzbach | Waltzing Matilda | Matilda of Tuscany | Sulzbach-Rosenberg | Empress Matilda | Matilda II | Sulzbach, Saarland | Herren-Sulzbach | Caroline Matilda of Great Britain | Matilda of Sulzbach | Matilda of Scotland | Matilda of Ringelheim | Matilda of Holstein | Matilda of England, Duchess of Saxony | Amberg-Sulzbach | Port Matilda, Pennsylvania | Matilda tank | Matilda Sissieretta Joyner Jones | Matilda's | Matilda of Germany (979–1025) | Matilda of Chester, Countess of Huntingdon | Matilda of Brabant, Countess of Holland | Matilda of Boulogne | Matilda (novel) | Matilda Joslyn Gage | Matilda FitzRoy, Duchess of Brittany | Matilda FitzRoy, Countess of Perche | Matilda FitzRoy, Abbess of Montvilliers | Matilda Chaplin Ayrton |