Simplify the following text for a Grade 9 native English-speaking person.
Original: By decree of Ptolemy III of Egypt , all visitors to the city were required to surrender all books and scrolls , as well as any form of written media in any language in their possession which , according to Galen , were listed under the heading `` books of the ships '' .
Simplified: By decree of Ptolemy III of Egypt , all visitors to the city were required to surrender all books and scrolls .