The library at Pergamum was not confiscated by any one person or group. Instead, it was gradually dispersed and its books were lost over time due to a variety of factors. One factor was the decline of the city of Pergamum itself, which lost its political and cultural importance in the Hellenistic period. Another factor was the rise of the city of Alexandria, which became a major center of learning and scholarship in the ancient world and attracted many of the intellectuals and scholars who had previously been associated with Pergamum. The library at Alexandria, which was founded by Ptolemy I Soter in the 3rd century BC, became the most famous library in the ancient world and is often credited with eclipsing the library at Pergamum. Finally, the library at Pergamum was also likely damaged or destroyed by various natural disasters, such as earthquakes and fires, which were common in the region.