composer Richard Wagner, such as Der Ring des Nibelungen, Vikings and the Romanticist Viking Revival have inspired many creative works. These have included novels directly based on historical events, such as Frans Gunnar Bengtsson's The Long Ships (which was also released as a 1963 film), and historical fantasies such as the film The Vikings, Michael Crichton's Eaters of the Dead (movie version called The 13th Warrior), and the comedy film Erik the Viking. The vampire Eric Northman, in the HBO TV series True Blood, was a Viking prince before being turned into a vampire. Vikings appear in several books by the Danish American writer Poul Anderson, while British explorer, historian, and writer Tim Severin authored a trilogy of novels in 2005 about a young Viking adventurer Thorgils Leifsson, who travels around the world. In 1962, American comic book writer Stan Lee and his brother Larry Lieber, together with Jack Kirby, created the Marvel Comics superhero Thor, which they based on the Norse god of the same name. The character is featured in the 2011 Marvel Studios film Thor and its sequels. The character also appears in the 2012 film The Avengers and its associated animated series. The appearance of Vikings within popular media and television has seen a resurgence in recent decades, especially with the History Channel's series Vikings (2013), directed by Michael Hirst. The show has a loose grounding in historical facts and sources, but bases itself more so on literary sources, such as fornaldarsaga Ragnars saga loðbrókar, itself more legend than fact, and Old Norse Eddic and Skaldic poetry. The events of the show frequently make references to the Völuspá, an Eddic poem describing the creation of the world, often directly referencing specific lines of the poem in the dialogue. The show portrays some of the social realities of the medieval Scandinavian world, such as slavery and the greater role of women within Viking society. The show also addresses the topics of gender equity in Viking society with the inclusion of shield maidens through the character Lagertha, also based on a legendary figure. Recent archaeological interpretations and osteological analysis of previous excavations of Viking burials has given support to the idea of the Viking woman warrior, namely the excavation and DNA study of the Birka female Viking warrior, within recent years. However, the conclusions remain contentious. Vikings have served as an inspiration for numerous video games, such as