One-time superior European city with lake by old road (5,4)
I believe the answer is:
Here is my best explanation:
'one-time superior' is the definition.
'european city with lake by old road' is the wordplay.
'european city' becomes 'liege' (Belgian city).
'with' says to put letters next to each other.
'lake' becomes 'l'.
'by old' becomes 'o' (common abbreviation eg in OE for Old English. I am not sure about the 'by' bit.**).
'road' becomes 'rd' (abbreviation).
(Other definitions for liege lord that I've seen before include "Feudal superior", "Oil ledger (anag) - feudal superior" and "Superior".)