Does St Alban's hold the record as being the oldest city in the UK? or the oldest mentioned city in the UK?

Colchester was granted city status on 20 May, 2022. It has long claimed the status of Britain's oldest recorded town, having (as "Camulodunum", its Roman name) been mentioned in 77 CE in the writings of Pliny the Elder. Archaeological evidence suggests that settlement dates back to Paleolithic times, while as the Celtic capital "Camulodunon" Colchester existed in the first century BCE.

Colchester is 80 km (50 mi) northeast of London, England.

By contrast, St Albans dates back to Roman times (as Verlamion) where it was a major town on the Roman road Watling Street. It lies in the Greater London area.

https://wiki2.org/en/Oldest_town_in_Britain+Newton

https://wiki2.org/en/Colchester+Newton

https://wiki2.org/en/History_of_St_Albans+Newton