Going away back to Saxon times, many of England’s monarchs had nicknames. From Alfred the Great to today’s Charles III, with the latter, as Prince of Wales already earning one as Charles the Woke.
Alfred reigned over Wessex from 871 to 899, and in being a strong warrior in battle against the Vikings earned his status. This contrasts with some European examples, ranging from Vlad the Impaler to Vladislaw the Elbow-High. Opposite to the latter was Edward I, that because of his height was called Longshanks.
Away back when, there was Ethelred the Unready. In Old English, “unraed” meant unwise counsel. Then there was Edward the Confessor, the only king to be canonized. Harold I was called “Harefoot” because of his speed and agility when hunting.