This is a series of short stories about a scientist who lived some centuries ago. Everytime he invents something of our own time like a bycicle, a television, a computer, a rocket. He's very clever. He has a pupil (Diciplus Simplex) to help him who always has bad luck: he is smashed to death or gets crushed by the machines of his master. There's one thing the pupil likes very much and that's sleeping. In the background of the stories you sometimes can see the adventures of a cat and a mouse.
The authors Bob De Groot and Philippe Liegeois (better known as Turk) published the first adventures of Leonardo in 1975. Other comics by these two men are Robin Hoed and Clifton.
Yes, Leonardo was based on the famous Leonardo da Vinci.