The Annales Egmundani name "Petronilla" as widow of "Florentius crassus comes filius Theoderici" but do not give her origin. The Chronologia Johannes de Beke records the marriage of Count Floris and "Petronillam Lotharii cesaris sororem". The Annales Magdeburgenses name "Gertrudeis comitissa de…Holland…soror Lotherii Saxonis ducis" when recording her rebellion in 1123.
Regent of Holland for her son Count Dirk VI during his minority. She founded the Abbey of Rijnsburg in 1133.
The Annales Egmundani record the death in 1144 of "Petronilla comitissa uxor Florentii crassi comitis" and her burial at "Rinsburch". The Chronologia Johannes de Beke record that "Petronilla…comitissa" became a nun at Rijnsburg after her husband died, and died and was buried there "X Kal Iun". Beke's Egmondsch Necrologium records the death "1144 X Kal Iun" of "Petronilla comitissa". 1
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