Playing Super Mario Land got me thinking about something which has bugged me for quite some time, and I think I've finally found an answer (though it's one I've suspected for quite a while.) Before I really get into this, though, I have to give a warning that this is just the thoughts of a nerd who over-analyzes things which the creators have not typically bothered to care about. But I just like to put myself in these fictional places and imagine how that particular world works. I dunno. If that makes me a loser, then so be it.
Back to the topic at hand. Super Mario Land takes place in a country known as Sarasaland, which is ruled over by the flamboyant Princess Daisy. Sarasaland (sometimes called Sarasa Land, but I don't like that as much) is divided into four kingdoms: the Birabuto Kingdom, the Muda Kingdom, the Easton Kingdom, and the Chai Kingdom. Each kingdom has its king (Totomesu, Dragonzamasu, Hiyoihoi, and Biokinton respectively.) However, each of these kingdoms, presumable, answer to the higher government headed by Princess Daisy. This effectively makes Sarasaland an empire. Okay, well it's never referred to as anything but "Sarasaland", so this isn't that confusing.
However, Super Mario Bros. 3 also divides into kingdoms. These kingdoms, whose rulers have gone nameless, are Grass Land, Desert Land, Water Land, Giant Land, Sky Land, Ice Land, Pipe Land, and Dark Land. Popular theories are that these areas are kingdoms beside the Mushroom Kingdom, or simply fake areas created for the fictional play which is Super Mario Bros. 3 (a theory I don't subscribe to.) However, given the government of Sarasaland, I think it likely that *at least seven* of these kingdoms are truly under the dominion of the larger Mushroom "Kingdom", which could be an improperly named Mushroom Empire.
This is further interesting to me because, other than Bowser, none of these kings have been seen in subsequent games. Could it be that after the events of Super Mario Bros. 3 the idea of an empire ruling over multiple kingdoms was abolished in favor of a more unified and defensible government? And why would they refer to the collective empire as the Mushroom Kingdom? Are there untold wars in which the Mushroom Kingdom dominated the poorer nations?
Only fan fiction can tell.
*Dark Land is the possible exception. Although if Dark Land were actually part of the larger Mushroom Empire, this could explain why King Bowser Koopa, despite regularly antagonizing the ruling family, would still be able to attend a number of sporting events and tournaments, and freely walk the streets. I think it possible that, given the other residences of the Mushroom Kingdom being Goombas and Koopas, Dark Land is a rebel state attempting to break free of the clutches of the Mushroom Empire.
