Horus: Prince of the Sun
太陽の王子ホルスの大冒険 (original)
Horus, a kid living in an unnamed Scandinavian/Eastern Europe culture of the Iron Age, recovers the Sword of the Sun from the rock giant Maug and learns from his dying father that he must return to his ancestral territory. In the process, he defends a village from the attacks of Grunwald, a warlord/ice demon and befriends the enigmatic Hilda, a lonely and beautiful girl who sings haunting songs (and who hides a terrible secret).
Starring Hisako Ookata, Hisako Ôkata, Etsuko Ichihara, Eijirō Tōno, Mikijirô Hira, Tadashi Yokouchi, Masao Mishima, Yukari Asai, Hiroshi Kamiyama, Yoko Mizugaki
Watch "Horus: Prince of the Sun" from streaming services Hoopla, Amazon released in 1968. It's a animation and drama movie, and has a rating of 6.6 out of 10 from Imdb which is usually fine for this kind of movie.