Series 5 - The Magic Yellow Stone
Tom, an English boy of sixteen finds a yellow stone on the ground near him covered with dust. When he cleans it with a cloth, he feels suddenly a strong wind that pushes him to the past. The first place where he lands is in the Alps mountains, meeting with the Hannibal army crossing the Alps to fight with it against the Romans. Hannibal appreciates his courage and valor and appoints him to command a cavalry troop of 2,000 horsemen. He participates in all the main battles of Hannibal.
In the long series (20 books until now) he is sent away to Alexander the Great and participates in his main battle as a general of cavalry and in Darius the Great and many more historian figures. The same he does with figures like Vasco da Gama, Francis Drake and more.