Ali Baba and the Forty Thieves is a book in Series 740 - Legends. My very first Ladybird Tuesday book was also in this series - A First Book of Aesop's Fables. It's not a large series, and it only contains 7 books.
Ali Baba and the Forty Thieves is one in a collection of stories called The Thousand and One Nights, based on ancient Persian, Arabian and Indian tales. They are linked by the story of Sheherazade, who managed to avert her execution by telling one of the stories to her sister each night in the presence of the Sultan, who couldn't bear to miss the end of a story and so kept delaying her execution until in the end she was forgiven.
The story has been re-written in simple text for younger readers. It follows Ali Baba, who never had much money to support his wife and son until he spots some thieves hiding their gold in a cave and learns the magic words ("Open Sesame") to open the cave and help himself. There follows a series of twists and turns as he and his family manage to foil the robbers.
Although most of the book follows the usual Ladybird style with text on the left and illustration on the right, some of the pages have both text and picture, and alternate pages have an illustration which is just red, black and white which jars a bit with the lovely colourful illustrations elsewhere. It's an exciting story though, and it's been well written to cater to young readers.
I'm joining in with Ladybird Tuesday at Being Mrs C. You can see all my previous Ladybird Tuesday posts here.