The lines and directions of streets can be remarkably old, especially in long established settlements. Street names can survive almost as long. New Walk has been new since 1785. More impressively, Cheapside will have been a market since the first post-Roman settlers arrived; the Angles in the C5th to C7th, working their way up the Nene and Welland valleys. The name survived the occupation of the town by the Danes, who settled in Leicester and widely throughout Leicestershire from the C9th; the survival of the old name in the middle of the town is particularly surprising since Leicester was no backwater – it was one of the Five Boroughs of Danelaw, a key administrative centre along with Nottingham, Stamford, Lincoln and Derby. The Danes took the names that were given; where they founded new settlements, they were given Danish names.
‘Leicester’ is the name given to the town by the Angles. A leigh, or lay, is a clearing in a wood. The walled towns they found, the decaying shells of Romano-British culture times were given the name caster (or derivatives like cester, caister); hence Leicester, a walled town in a forest clearing.
A fabulous resource is available for looking at the geographic location of place names by origin; the Key to English Place-Names (“KEPN”), a tool from the University of Nottingham Institute foe Name-Studies.