The Great Library of Alexandria was the most important library of the ancient world. It was founded around 300 B.C. by Ptolemy I, and was greatly enhanced by the later Ptolemaic rulers, when Alexandria served as the cultural centre of the Hellenistic world. Euclid and Eratosthenes were among the many Greek mathematicians who worked at the library. A story goes that the library attempted to obtain copies of all known scrolls of any consequence, even searching incoming ships (Alexandria was a first rate seaport) for scrolls which could be copied. The exact number of scrolls that it contained is not known, although estimates have ranged up to 700,000 scrolls. Alexandria became a centre for learning as well as a repository of knowledge.
The exact fate of the library and its contents also unknown. Ancient sources contain conflicting accounts; as well, the fact that there were two significant libraries, the royal library and the Serapeum, leads to some ambiguity. Possibly the royal library was accidentally destroyed in 48 B.C. by Julius Caesar, and the Serapeum was destroyed by religious fanatics under the leadership of Patriarch Theophilus of Alexandria in 391 A.D. These dates may not represent the dates when the library's contents disappeared. Few of the works of the library survive, but part of the catalogue does survive, tantalizing us about the treasures contained in the library.