Why is "Dick" a nickname for Richard?

Richard is derived from the Germanic “ric” (ruler, leader, king) and “hard” (strong, brave, court), meaning ‘powerful leader’ as well as ‘King’s Court’
The name Dick was used colloquially to mean a common man.
Richard and Ricard were equally popular in the Middle Ages, which led naturally to diminutives—such as Rich, Richie, Rick, and Ricket. Rhyming nicknames were also fairly common in the 12th and 13th centuries, and so we also have Hitch from Rich, Hick and Dick from Rick, and Hicket from Ricket. Some became surnames or parts of surnames.

But in reality any man can be a Dick!

GA @blueiiznh
Can you explain how Peggy is a nickname for Margaret?

@Blueroses The reason for Peggy is summed up best here. We have several of these in my family and for the life of me I couldn’t remember this off the top of my head and had to look it up again.

I always thought there was some douche bag named Richard that everyone starting calling dick.

There’s a thread on this somewhere.

The one I never uderstood was Jack being the nickname for John. They are both four letters so it isn’t like it is a shortened version of John or anything. And they don’t sound anything alike.

Probably the same reason Bill is short for William and Bob is short for Robert.