0ur local Tyneside city Newcastle originally grew around a Roman settlement called Pons Aelius so took on that name.
Years later it became Monkchester.
Then later again when the Castle was built in 1080 by William the Conqueror's eldest son, Robert Curthose it took on the name of Newcastle.

Imagine if the Castle hadnt been built?
Newcastle United would have been 'Pons Aelius United' or 'Monkchester United'