Mammarian Mother Manchester etymology, or: who said breast?

Manchester, Northwest England.

The name Manchester originates from the Latin name Mamucium or its variant Mancunium. These are generally thought to represent a Latinisation of an original Brittonic name, either from mamm- ("breast", in reference to a "breast-like hill") or from mamma ("mother", in reference to a local river goddess).  

Both meanings are preserved in languages derived from Common Brittonic, mam meaning "breast" in Irish and "mother" in Welsh.[13] The suffix -chester is a survival of Old English ceaster ("fort; fortified town").[14]

(Wikipedia, https://en.wikipedia.org/wiki/Manchester)