Where do Our Nicknames Come From?

Peggy for Margaret and Chuck from Charles? What's up with that? 

Many nicknames we have today sound a little bit strange, but we just take it for granted that a Katherine may be called Kate, or a Richard be Dick, though these nicks don't really sound very much like the original name. Why is this?

Let's start with some -ck names. Way back in the middle ages, a common way to make diminutives of names is to add -kin, -in, or -cock to the end. Thus, John  became Jankin or Jenkin, which eventually became shortened to Jakin, which in turn became Jack. Many of these names today survive in surname form (i.e., Jenkins, Wilkins, Perkins, Tompkins, Wilcox, Johncox, etc.) though there are not many used as first names anymore.

Adam = Adekin, Adkin, Adcock 
David = Dawkin, Dakin
Francis = Frankin, Frank
Geoffrey = Geffrin
Gilbert = Gibbin
Henry = Hawkin, Henkin, Hankin, Hank, Henecok
John = Jankin, Jenkin, Jakin, Jack, Johncock
Lawrence = Larkin
Luke = Lukin, Luckin
Matthew = Makin, Maykin, Maycock
Nicholas = Colin, Cole
Peter = Peterkin, Parkin, Perkin
Philip = Philkin
Ralph = Rawkin
Robert = Robin, Hobkin
Roger = Hodgkin, Rodgkin
Simon = Simkin
Thomas = Tonkin, Tomkin, Tonk
Walter = Watkin
William = Wilkin, Wilk, Wilcock

Rhyming names also have been popular diminutive forms of names. For example, Robert spawned not only Rob, but Hob and Dob as well, which in turn became Hobkin and Dobkin. 

Other examples are:

Agatha = Ag, Aggie, Tag, Taggie
Andrew = Andy, Dandy
Robert = Rob, Bob, Hob, Dob, Nob
Roger = Rodge, Dodge, Hodge, Nodge
William = Will, Bill

The Norman Invasion of England in 1066 changed the language as well as the naming pool. The Normans introduced many new sounds into the language that the native populations had difficulty with. The "r" sound was one of these, which led to it being dropped or changed in many diminutive forms of names.

For example:

Barbara = Babs
Dolores = Lola
Dorothy = Dolly
Florence = Floss, Flossie
Mary = Moll, Molly, Polly, Maisie, Maidie
Harold = Hal
Margaret = Maggie, Meg, Meggie, Peg, Peggy
Sarah = Sally, Sadie
Frances = Fanny
Brigid = Biddy
Teresa = Tess, Tessa, Tessie

-ch and -th sounds were pronounced like "k" and "t" in these days as well. Surviving today are the pronunciations of Thomas, Theresa and Anthony (pronounced like Antony in Britain still). Richard was pronounced more like Rickard, thus giving rise to the pet forms Rick, Hick, and Dick.

Some examples:

Dorothy = Dot, Dodie
Elizabeth = Bess, Bessie, Betty
Esther = Ettie, Essie
Catherine = Kit, Kitty, Kate
Matthew = Matt
Christopher = Kit
Theodore = Ted
Theresa = Tess, Tessie
Anthony = Tony

Another pet name trend was to use "mine" in front of a name. This eventually contracted to add an "n" sound to the beginnings of some names. For example:

Ann = Nan, Nannie
Edward = Ned
Helen = Nell, Nelly
Isabel = Nib, Nibbie
Oliver = Noll

Present day finds us adding -ie, -y, -i or other "ee" sounds to a name (or name's syllable) to form the diminutive. This began in Scotland and spread to the rest of England, and then were brought to the USA. In Scotland, Christie was originally a man's name, short for Christopher. Likewise, Josey was short for Joseph (i.e., the Clint Eastwood movie The Outlaw Josey Wales).

Here's a table of some Medieval English names that are still in use today, with their diminutives: