Norfolk County and its townships were originally named by Upper Canada Governor-General John Graves Simcoe, in the mid-1790s. County boundaries were redrawn in 1829, but other than that, names stayed much the same for almost two centuries. (For a list of community name changes over the years, see Place Names' description of each population centre.

During that period various hamlets grew into villages and towns, each with its own community government and street naming conventions -- explaining much of the name duplication.

This story was duplicated in most Ontario (formerly Upper Canada) counties, ensuring the Provincial Government had more and more layers of municipal government to deal with.

In the mid-1970s the Provincial of Ontario decided to streamline government organization in the name of efficiency and cost-saving, merging counties into larger "Regions." 
Norfolk County merged with the county immediately east, Haldimand County, to form the Region of Haldimand-Norfolk in 1973. (Similar county mergers occurred all across the province.)

That meant the end of Norfolk County. Historic township names disappeared as well.

The marriage of Haldimand and Norfolk was not a happy one. After about 15 years of trying to work things out, local representatives appealed to the Provincial Government for a divorce. The Provincial Government declared counties a level of municipal government best left in the past, but offered the former Haldimand County and Norfolk County another choice: they could each become "towns" under the new (1970s) tier flattening arrangement.

On 1 Jan 2000 the former County of Norfolk became the Town of Norfolk County. (Yes, the Town of Norfolk County. Legally, Town is the operative word here, County is just part of the descriptive name.) And a new municipality, complete with its own town council was born.

Yet, in the real world -- and as far as the post office was concerned -- nothing's changed. Norfolk was still comprised of towns like Port Rowan, Delhi, Port Dover, Waterford and Simcoe, and a slew of smaller villages and hamlets.