Gerolf I of Middle Friesland
Gerolf I of Middle was born about 0810 in Belgium.  He died after 0839.

 Daughter of Corbic
Daughter of was born about 0815.  Daughter of is no longer alive.

 Gerolf II Count of West Friesland
Gerolf II Count of West was born before 0839 in of Netherlands.  He died after 0885.