Predecessor
A few years prior to Flintheart's debut, another character was described as the World's Second-Richest Duck. His only appearance took place in Carl Barks' story "Turkey With All the Schemings". In that story, Donald Duck found himself unable to afford a Christmas dinner and decided to trick Scrooge McDuck into paying for dinner for him. To do so, Donald posed as a South-American businessman named Petrolio de Vaselino and had Scrooge take him to the Ritz. While eating dessert, Donald accidentally ate his phony moustache, making him look like the Duke of Baloni, described by Scrooge as the World's Second-Richest Duck. By coincidence, Scrooge had a newspaper article talking about the Duke visiting Duckburg. The fact Scrooge remained willing to make business with him suggests the Duke never claimed to be richer than him. Not much else is known about the real Duke since he just made a cameo at the beginning of the last page and his only purpose in the story was cluing (via his presence) Scrooge to the fact he was dealing with an imposter. After removing Donald's wig, Scrooge was determined to make Donald pay. He asked the waiter if the restaurant was for sale and was told it's for sale for one million dollars. In a surprising (since he had spent the whole last night trying to make sure Donald wouldn't leave and force him to pay the bill) move, Scrooge quickly pulled the required amount from his pockets and bought the restaurant. Donald then was forced to wash the dishes to pay the bill. It's never said when Flintheart became richer than the Duke or if the two ever met.
Read more about this topic: Flintheart Glomgold