Seisyll ap Dyfnwal
Seisyll was born in Abergavenny, Monmouthshire, England.  He died on December 25th, 1177 in Abergavenny Castle, Monmouthshire, England.

 Dyddgu verch Owain
Dyddgu was born in 1113 in Abergavenny, Monmouthshire, Wales.  She died before 1156.

 Gwladus verch Seisyll
Gwladus was born about 1135 in Monmouthshire, Wales.