borough (district), administrative and historic county of Cheshire, England, extending from the River Mersey to the River Dee at the southern end of the Wirral peninsula. Ellesmere Port is very much a 20th-century creation. The building of the Ellesmere Canal in 1795 saw the beginnings of industrial development, but it was the opening of the Manchester Ship Canal in 1894 that marked the emergence of Ellesmere Port as a major industrial centre. Petroleum refining began after World War I. After World War II, as refining and chemical industries expanded at Stanlow, the town grew rapidly. Other industries followed, including motor vehicle manufacturing. In the west of the borough are the residential communities of Neston and Parkgate. The latter was an 18th-century port for ships from Ireland. The borough also includes a rural area and several villages. Area 34 square miles (88 square km). Pop. (2001) 81,671.