The Hans Christian Andersen tale about a soldier who finds three underground princesses with enchanted dogs is The Tinderbox. Andersen published it in 1835, making it one of his earliest fairy tales.
A soldier returning from war meets a witch who asks him to enter a hollow tree. Inside, he finds three chambers containing treasure guarded by dogs with unusually large eyes. In return for retrieving a tinderbox, he gathers money for the witch but keeps the magical object.
The tinderbox can summon the dogs, who carry out the soldier’s commands. After losing his fortune and being sentenced to death, the soldier uses the tinderbox to call the dogs. They bring him to the royal court, where he ultimately becomes king and marries a princess.
The story draws on traditional folk-tale motifs involving magical helpers, underground treasure, and a socially low-born hero who rises to power. Andersen’s version is brisk, comic, and more openly dependent on luck and supernatural assistance than some of his later, more tragic tales.