Yngling Clan

The Yngling Dynasty was started in 1020 AD, according to the Edda, and even composed other clans, such as the Fairhairs, and the Scylfings. They were believed to be the descendents of the Vanir god, Freyr, and the Jotun, Gerđr. It's proclaimed founder was King Fjolnir. Over the years now, it has been growing in power, with more and more of the extended family coming together for the glory and thrill of Raiding.

Awkward bloodline
The Yngling Clan isn't proud of it, but it wasn't exempt from the inbreeding ways of other royal bloodlines, it doesn’t continue it, but its still a black mark on their history.

To clarify, many of Gerđr's halfblood cousins (half jotun/god half human grandchildren of Loki and Kári) would marry into the family. And even after the half giants, inbreeding was thing. But not anymore.

Divine blood
It is believed that many Demigods and half giants made up the original few generations, with Vlanlandi, grandson of The Demigod King Fjolnir, marrying Drifa, the granddaughter of Jokull, the Frost giant, and Gerđr's cousin. Then, an unidentified daughter of Auđ the Rich, great grandson of Loki and Sigyn, would marry Vlanlandi's son, Visbur. Visbur had an unidentified second wife, too. Visbur's grandson, Domar married Drott, the granddaughter of the Norse god, Ríg. Then Domar's great grandson, Agne, married Jokull's Daughter, Skjalf, with is disgusting and is a tragic story for another day. Somewhere after that, there's mention of Gauti, a mythical, god ancestor of the royal family of the Geats.

All culminating into Ragnvald the Mountain High, the ancestor of the current leader, Thursfotr (No, that is not a misspell, that Is his actual nickname).