SIEGFRIED I von SPANHEIM-ARCH

SIEGFRIED I's father was ENGELBERT I MARGRAVE de ISTRIA and his mother was HEDWIG von EPPENSTEIN.  His paternal grandparents were SIEGFRIED COUNT von SPONHEIM and RICHARDIS von INNGAU.  He was an only child.  He died about 1140.¹ 

They had a son named OTTO COUNT.