Sancho I, ruler of the kingdom of Léon in the north of modern-day Spain, was overthrown by rebel nobles in A.D. 958. Their motive, even by the turbulent politics of the day, was an unusual one: The ...

Astronomy, medicine, theology, physics, arithmetic, poetry — there was seemingly no discipline left untouched by the renowned polymath Avicenna, celebrated today by Google Doodle in honor of what ...