King Croacus was the title bestowed onto the ruler of the Floro Kingdom, the exception being Queen Croacus II, because she was a woman instead of a man. King Croacus IV is the only leader actually seen in-game, but there is a palace in the Floro Caverns with pictures on all four leaders. There are signs underneath each picture that says the time that they he/she ruled, what accomplishes he/she made to the Floro Kingdom and how he/she died.
Also known as the White Maiden, Queen Croacus II (the first queen but the second ruler, explaining why she is the second) is the daughter of the King Croacus and the second ruler of the Floro Kingdom. During her father's insanity, she was arrested by her own father for disagreeing with his views. After his father wilted, she was set free of prison. People agreed with her views, and so she became Queen Croacus II.
Like her father was at first, Queen Croacus II was very popular. The White Maiden reduces taxes and studied diseases, thus helping many sick or poor Floro Sapiens. She also wrote The Flictionarian, a prehistory of the Floro Kingdom that is not seen in-game. When she grew old, she worried over having many heirs fight for the crown. So, she had only one child before she died, who would later become King Croacus III.