Simplify the following text for a Grade 10 native English-speaking person.
Original: The reconstituted County Durham lost territory to the north east ( around Gateshead , South Shields and Sunderland ) to Tyne and Wear and to the south east ( around Hartlepool ) to Cleveland .
Simplified: The boroughs of Hartlepool and Stockton-on-Tees became a part of the new non-metropolitan county of Cleveland . The metropolitan county of Tyne and Wear became responsible for Gateshead , Sunderland and South Tyneside .