Of all the dignitaries throughout the entire human history, Queen Elizabeth II's portrait has appeared on the most number of banknotes from countries across all the continents on this planet. Her image appear on Canadain banknote when she was as young as 8, then Princess Elizabeth, before her uncle abdicated, making her father the King of England, hence making her the next in line for the throne.
The Washington Post did a wonderful piece on QE2 and the author summarized it rather neatly in an infographic potraying the countries and years of which QE2 appeared on their banknotes. All in there are 33 countries involved since her ascension to the throne in 1953. And today, less than half of those countries still retain her portrait.
The full article is here : Every Country that Feature Queen Elizabeth II on it Currency
So here's to all you collectors of QE2 banknotes.