Thyra "Danebod" Haraldsdatter, Dronning af (Vest)Danmark - Who was the father of Thyra Danebod?

Solving this mystery I suspect will also solve another - the uknown father of "Herfast de Crepon".
Emma of Normandy is listed as having 3 grandfathers, which of course is impossible. Two of them are Harald Bluetooth and "unknown de Crepon" who is also the father of Herfast de Crepon. I have also seen Thyra referred to as "Reine de Crepon.". So that makes me want to equate Harald Bluetooth with "uknown de Crepon", making him the father of Herfast de Crepon. So, can we find a connection between Thyra and Crepon in Normsndy. It might be an English king who bestowed that title upon her of "Reine de Crepon " ; and where in fact was Harald Bluetooth born? Could he have been born in Normandy?

Here is a firther clue: It is told that Styrbjorn Olofsson sailed from Norway with his sister Gyrid to confront Harald Bluetooth in Denmatk. He ended up swapping his sister Gyrid, who became Harald's 2nd wife for Tyra, Harald's daughter.
Now, in some places you will see the mother of Herfast de Crepon listed as " Cyrid, Queen of Sweden". I think this is Gyrid, Harald Bluetooth's srcond wife, which makes Hatald Bluetooth one and the same with the father of Herfsdt de Crepon, whose unknown father was given the invented name of " Herbsstus de Crepon"