Guineas took their name from the gold brought from Guinea by the African Company in 1663, who, as an encouragement to bring over gold to be coined, were permitted by their charter from Charles II. to have their stamp of an elephant upon the coin. When first coined they were valued at 20s., but were worth 30s. in 1695. There were likewise fivepound pieces, like the guinea, with the inscription upon the rim.
This text comes from a footnote on a diary entry in the 1893 edition edited by Henry B. Wheatley.
Chart showing the number of references in each month of the diary’s entries.