Morgan family of Waterford City

Hi all,

I descend from a William Morgan who died in Waterford in about 1743. He was the mayor of Waterford in 1735 and was also an Alderman and/or sheriff at different times. His son William Morgan was Mayor in 1754 , and he was married to Sarah Grogan, daughter of John Grogan of Johnstown, County Wexford.

I am trying to find out who William Morgan senior's parents were, and where this Morgan family came from ?

In the list of mayors and sheriffs of Waterford that is readily found in various publications on the internet, the next prior Morgan in that list is John Morgan, Sheriff in 1706 and William Morgan, Sheriff in 1702. There are also other Morgans listed that date back to the 15th century such as Nicholas Morgan, mayor in 1457; John Morgan mayor in 1466; Patrick Morgan sheriff in 1483; John sheriff in 1511-1516; Nicholas sheriff in 1523; John mayor in 1526 and 1530; John sheriff in 1638; Peter sheriff in 1645; Andrew sheriff in 1648. 

If anyone has any knowledge of this family and it's ancestry I would be interested to hear from you.