Names Change: We have proper names and we have shorter nicknames, and many of them go back a long way.
Robert became Bob. How? Rhyming names were popular in the Middle Ages, so Robert became Rob and also Hob, Dob, Nob and finally Bob.
Richard became Rick, Hick and then Dick. William became Will, Gill and then Bill.
How did John become Jack? Again, go back to medieval England. The name went from John to Johnkin to Jankin to Jackin to Jack.
Charles in Middle English was Chukken and that’s probably where the nickname originated.
According to one linguistic theory, James was shortened to Jems then Jem and later Jim.
Margaret became Maggie, then Meg and into Peg and Peggy.
English and French speakers took the “r” in Sarah and changed it to an “l” so Sarah became Sally and Mary became Molly.