They are apparently very different, perhaps they do share certain similarities in their stories, religion, cultural rituals as they share the same geography. They each have their own gods with different roles, Norse gods are granted with the knowledge of past and future, Celtic gods are believed to be “The shining one” called “lugus”. The gods lived in a heavenly placed called Asgard in Norse mythology, whereas Celtic gods lived on earth before the humankind. Their heroes are different. The Norse mythology has a lot of Christian influence, in fact, most of the literature work was produced in Christian monasteries. The Celtic mythology comes from mainly Roman sources and other stories were written by the medieval Irish and Welsh monks. The evidence
