Which Grimm tale is traditionally KHM 1, the first story in the collection?

Which Grimm tale is traditionally KHM 1, the first story in the collection? The Frog Prince is KHM 1. Its fuller German title is The Frog King, or Iron Heinrich, and it opens the Brothers Grimm’s famous collection of folktales.

The Grimms published the tale in the first edition of Kinder- und Hausmärchen in 1812. In the story, a princess loses a golden ball in a well, and a frog retrieves it after she promises his companionship. Her father then insists that she honor the promise, leading to the frog’s transformation into a prince.

The familiar idea that the princess kisses the frog is not the central action in the Grimm version. In the best-known early text, she throws the frog against a wall, after which the enchantment breaks. The tale is classified as ATU 440, a wider folklore type sometimes called “The Frog King.”