Brida

Brida grows up in Ragnar's hall just like Uhtred: Saxon by birth, Dane by upbringing. She's quick, afraid of nothing, and to her Ragnar is the only father who counts. She and Uhtred become lovers young, in a life where the northern gods feel far more alive than the Saxons' god. After Ragnar's death the two flee to Wessex together.

Among Alfred's Christians, Brida doesn't fit. When Uhtred marries Mildrith, she leaves and goes back to the Danes. From then on, every reunion shows they no longer want the same thing.

Brida turns up beside Ragnar the Younger, son of the man who raised her. Together with Uhtred they storm Dunholm, the stronghold of Ragnar's killer, Kjartan.

For Brida it's personal. Avenging Ragnar matters more to her than any deal with the Saxons.

Brida stays with Ragnar the Younger at Dunholm while Uhtred remains bound by his oaths to Alfred. Their friendship hangs by a thread.

When Ragnar is murdered in his sleep, Brida loses her last tie to the family that raised her. From here on she fights for herself.

Brida is with Cnut when the Danes invade Mercia. At the battle of Tettenhall, she is the one who kills him. Soon after, she's taken prisoner by the Welsh.

The alliance with Cnut was never easy. Brida lives by her own code, and when she feels betrayed, she doesn't forgive.

Years later Brida returns at the head of a band of fanatical Danes, set on wiping out the Saxons. To her there's no longer any difference between the Christians and the Danes who make deals with them. Her war puts her and Uhtred on opposite sides for good. She dies this season, and Uhtred burns her body the Danish way.

Emily Cox returns in Seven Kings Must Die for a single scene: the vision of Valhalla Uhtred has at Brunanburh, where old friends and enemies wait for him.

In Bernard Cornwell's books Brida is also Uhtred's childhood friend who sides with the Danes, but her path differs a lot from the show's.