....

Genealogy

http://fmg.ac/Projects/MedLands/GERMANY,%20Kings.htm#KonradSwabiadi...

King Konrad had one illegitimate son by Mistress (1): ---. The name of King Konrad's mistress is not known. Benoist-Méchin says that she was a Sarracin from Lucera but does not cite the corresponding primary source[703].

b) KONRADIN (Lucera [1252]-hanged Lucera 1269). The primary source which confirms his parentage has not yet been identified. He was captured by Charles I King of Sicily [Anjou-Capet] at the siege of Lucera