From Tudor times

The powers of the Mayor as Chief and sometimes Sole Magistrate were greatly increased.

This resulted in a great increase in their personal importance as these following examples of mayoral powers show:

The power to arrest those disturbing the peace and persons carrying offensive weapons in fairs
Power to regulate the size of loaves of bread and to seize bread of unlawful size and pillory the bakers responsible
Powers to search premises suspected of unlawful gaming
The power to compel persons to go into service, and to deal with matters relating to servants and apprentices
The power to deal with Dyers suspected of using logwood in dyeing

By the Seventeenth century, the Mayor had in many Boroughs become all powerful and in many instances his powers included:

Chairman of the Council or other governing body of the town (for example, the Alderman, Capital Burgesses, Masters, Approved Man, Portmen, or Brethren)
Chief Magistrate often presiding at Quarter Sessions as well as Petty Sessions
President of the Civil and Manorial Courts of the Borough, sometimes sitting with the Recorder or the Town Clerk, and sometimes alone
Borough Coroner
Clerk of the Borough Market(s)
Keeper of the Borough Gaol
The appointment of most Borough Officers, including in some towns the Town Clerk and Chamberlain
The creation of Freeman, often for a fee
Admiral of the Port - title retained today in several seacoast towns such as Southampton, Poole and Kingston-upon-Hull

By the Eighteenth century, the position of Mayor in this country had become one of considerable power and the position was, and still is, regarded as the pinnacle of achievement for service to the local community.

In 1835, the legal position of the Mayor was regulated by Parliament, who laid down a clear definition of the precise attributes of the modern Mayor thus restricting and regulating by statute the rights of the precedence of the Mayor.

By the nineteenth century, a Mayor could be the centre of all political activity with the terms of office lasting often two to four years. By attending a large number of committees, the Mayor could hold the whole Council together and co-ordinate and integrate its activities. The political role of the Mayor, rather than the social and ceremonial role, was clearly far more important in this era than it is today.