Many European royals had the same name, so they often were differentiated by numbers such as Charles I, II or III. Even this became difficult to remember, so people gave their kings nicknames.
A minister's wife and worship leader used to lead the congregation in that old song, "Count Your Blessings." When the congregation got to the part where it would sing, "Count your blessings, name them one by one/Count your blessings, see what God hath done," she would say, "One is not enough. Let's count them by twos."