The House of Wessex, also known as the House of Cerdic is the ruling house of the kingdom of Wessex. It's the oldest and one of the most powerful in England. It was founded 300 years before the events of Vikings. Members are called Cerdicingas in Old English.
On a windy summers day in 495, 5 Saxon ships landed in Hampshire. Commanding them was the chief Cerdic, a Saxon warlord with possible mixed Celtic heritage. With him was his son Cynric. According to legend, Breton rulers had invited migrating North Sea Germanic peoples like Saxons, Angles, Jutes and Frisians to Brittan to serve as mercenaries. Like their northern cousins centuries later, the Saxons had become fascinated by the fertile lands. With increasing power-vacuum after the Romans had left, soon various warlords where launching campaigns of conquest on all lands south of Hadrian's Wall.
Cerdic is said to have fought the local Breton king Natanleod for a decade before killing him and seizing control of the region, which later became known as Wessex. Cerdic and Cynric claimed decent from the god Woden. Cynric took up his father's mantle after his death and continued his line and house, which at the beginning the 9th century was headed by king Ecbert. Despite their claimed divine ancestry, the Cerdicingas eventually converted to Christianity, preached by Irish missionaries.