After completing study of the Old Kingdom of Egypt, our Story of the World moved back to Mesopotamia. Since we have been also reading integrated literature, I decided it made absolute sense to study what is possibly the oldest piece of known literature, The Epic of Gilgamesh.
Fortunately, a children's version of the Sumerian legend is available, a picture-book trilogy by Ludmila Zeman; Gilgamesh the King, The Revenge of Ishtar, and The Last Quest of Gilgamesh. Since it was unavailable at my local library, I decided to go ahead an purchase it, and I'm glad I did. Though large modifications were made to the story, such as the glaring change of the Sumerian Inanna to the more commonly-known Babylonian counterpart Ishtar, the work did an excellent job in capturing the essence of the epic in both words and illustration. Both my kids (ages 6 and 8) enjoyed the story, and came away with some familiarity with one of the world's oldest stories.
I have through the course of homeschooling reminded my children of the phenomenon of the same stories being told and retold, so it was especially enlightening for them to see this occur in even the world's oldest stories, as Utnapishtim's flood story (which predates and clearly mirrors the Biblical flood story) is included in this children's version of Gilgamesh as well.