The Brothers Lionheart (Swedish: Bröderna Lejonhjärta) is a children's fantasy novel written by Astrid Lindgren. Well established as one of the most widely read and beloved books for children in Sweden, it was originally published in the autumn of 1973 and has since been translated into 46 languages. Like several of Lindgren's works, the book has a melancholy tone, and many of its themes are unusually dark for the children's book genre.
https://en.wikipedia.org/wiki/The_Brothers_Lionheart