BA-BOOM

Wasn't it only the werewolves (maduke) who wanted her dead and he just used the humans as a way to do and the nobles didn't know he had a daughter he only introduced her not as his daughter only to rai but thidy is only my opinion

What i understood from the events of 820 years ago. Was this: Maduke wanted to be lord as he felt Muzaka wasn't good enough. The traitor nobles wanted to rule Lukedonia, and the word with power. Not rule in the background protecting worthless humans. Of course, it was impossible to that with the noblesse alive (Raizel) so they met up with Maduke and created a plan that would get Muzaka and Raizel to fight each other/kill each other. Killing two strong birds with one stone, so they used the humans as their pawns. Maduke had one of his werewolf henchman disguised as a human, he hid all his power to avoid detection. He armed himself with a human crossbow and killed Ashleen. They successfully fooled Muzaka into believing that the humans killed his daughter, blinded with rage he went on a killing spree againts humans. Muzaka's was Raizel only friend and he had to stop him from killing more humans. So they pretty much fought and fought. In the end, Muzaka and Raizel dissipated and the traitors/future lord deemed themselves the winners.
..... Muzaka did avoid telling people he had a daughter because he knew that someone would harm her to go against him... Maduke must had people following him around or something along those lines because he was able to figure out that Ashleen was his daughter. Since his plan was only possible with the help of the traitor leaders, he most likely told them, or not.. anything is possible. We do know that the Nobles played a hand in the death of his daughter.

But from what I understood it wasn't the Nobles who helped in this assassination, but it was that bunch of traitor nobles, who did it /and whom they fought in Lukedonia/

That's what i said <3

It wasn't the traitor nobles it Was the King of nobles and the clan leaders and after they took part of this, they put themselves to internal sleep --((that explains why the died for a unknown reason))

That wouldn't make sense at all, why would the old king conspire whit the wearwolves to get rid of Muzaka and Raizel? When the old King loved raizel. Also they put themselves to internal sleep because they lived for too long and wanted to give the newer generation the chance to rule. And anyone who agreed with the old king views would also follow him to internal sleep. The only reason gejutel stayed serving as a clan leader was because the newer generation would need a guide, someone with wisdom. You should probably re read the story again. Actually more like re-read this part: http://www.mangago.zone/read-manga/noblesse/mf/v03/c196/