Newcastle upon Tyne (RP: /ˈnjuːkɑːsəl/ NEW-kah-səl, locally /njuːˈkæsəl/ new-KASS-əl), or simply Newcastle, is a city and metropolitan borough in Tyne and Wear, England. The city is located on the River Tyne's northern bank and forms the largest part of the Tyneside built-up area. Newcastle is also the most populous city of North East England. Newcastle developed around a Roman settlement called Pons Aelius and the settlement later took the name of a castle built in 1080 by William the Conqueror's eldest son, Robert Curthose.