Simplify the following text for a Grade 9 native English-speaking person.
Original: Uruk is eponymous of the Uruk period , the protohistoric Chalcolithic to Early Bronze Age period in the history of Mesopotamia spanning c. 4000 to 3100 BC , succeeded by the Jemdet Nasr period of Sumer proper .
Simplified: Uruk gives its name to the Uruk period , the protohistoric Chalcolithic to Early Bronze Age period in the history of Mesopotamia , about 4000 to 3100 BC . This was followed by the Jemdet Nasr period of Sumer proper .