Friedrich II Von Pfirt
Friedrich II Von was born before December 1180.  He died in 1233 in Asassinated by (son?) of Louis II.

 Heilwig Von Urach
Heilwig Von was born about 1190.  She died in 1262.

 Alix Von Pfirt
Alix Von was born about 1208.  She died about 1285.

 Ulrich II Von Pfirt
Ulrich II Von was born about 1210.  He died on March 1st, 1276.