In England, the Mayor is the later descendant of the feudal lord's bailiff or reeve.
The Chief Magistrate of London bore the title of Portreeve for considerably more than a century after the Norman Conquest.
This official was elected by popular choice, a privilege secured from King John. By the beginning of the twelfth century the title of Portreeve gave way to that of Mayor as the designation of the Chief Officer of London.
The adoption of the title by other boroughs followed at various intervals.
The title of Mayor given to the head of the Corporation (Council) is comparatively speaking an innovation which was introduced by the Municipal Corporation Act 1835.
Like today, the Mayor was acknowledged as the "first citizen" of the town, he had a Council (under differing names) to assist him, he was a 'Custodian of the Peace' - the name for early Magistrates, and he would normally preside in the Borough's civil and criminal courts.