George V, Three Kings Sixpence Fine, 1936
These 1936 silver sixpences have the portrait of King George V on them, but they have a far more interesting history. King George V died and his son became King Edward VIII and most of these Sixpences were struck during the reign of King Edward VIII. In December of that year Edward abdicated and his brother became King George VI.
While the portrait is that of King George V who knows who was actually on the throne when they were struck. It is an interesting conundrum which will never be figured out.