2,300 years ago, the rulers of Alexandria set out to fulfill an audacious goal: to collect all the knowledge in the world under one roof. In its prime, the Library of Alexandria housed an unprecedented number of scrolls and attracted some of the Greek world's greatest minds. But by the end of the 5th century CE, it had vanished. Elizabeth Cox details the rise and fall of this great building. [TED-Ed Animation by Inna Phillimore]