Why do some English first names include a variety of acceptable, yet unrelated, nicknames? (Richard, Charles, James, etc.)

Question

There are so many of these traditional English names that have, seemingly, unrelated nicknames. Who started this and are we still doing it with names today?

In: 1

Answer 1

Wait until you hear Spanish nickname conventions!

Jose > Pepe

Francisco > Paco

Ignacio > Nacho