Pronunciations have changed with literacy and dialect. (ich) sounded like (aick) in proto-Germanic, making Richard phonetically more similar to modern Ricardo.

Pronunciations have changed with literacy and dialect. (ich) sounded like (aick) in proto-Germanic, making Richard phonetically more similar to modern Ricardo. Rhymes are also popular for nicknames, especially if you've got a village full of people with the same name, also especially if the rhyme sounds like something else. Ryke(r)/Rick/Rickon, Dyke/Deek/'Deacon'/Dick, Hyke... that's more of a surname, and perhaps more common to people who encountered the Scandinavians. There's also Richert, Ricard, and Ricart from the same root. Modern 'Richard' is softer (ich), almost like (ish), and may have been pronounced like Rishard in places before the modern compromise.