Monarchy

A monarchy was a system of government in which an individual or small group, such as a family, ruled over an entire realm. These individuals were known as monarchs and were often referred to with titles such as king, queen, prince or most commonly, princess. Other titles were rare, but did exist, such as lord and master. The succession line of power tended to vary from country to country, with the Crystal Empire being a dynastic system of rulers hailing from the Amore dynasty, whereas Equestria appeared to appoint rulers based off merit.

Countries with monarchic governments were often called kingdoms or empires.

The families of monarchs were known as royal families.

Behind the scenes
Monarchies have played a major role in My Little Pony mythology since Generation 1, with countless kingdoms being visited in early stories. Not much of these kingdoms were ever displayed, and some were never shown or even mentioned, but were still implied to have existed in some fashion, such as various princes coming to the ponies for aid. This trend didn't quite continue into My Little Pony Tales, but kingdoms were still mentioned and depicted, such as Squire's kingdom and the Isle of Pony.

Monarchies remained very much a thing into Generation 4. They were toned down in comparison to Generation 1 cartoon and comic stories, so new kingdoms were implied or visited in every other story, but instead a small, but fairly consistent mythology among a group of kingdoms was instead employed. The primary kingdom was the land of Equestria. which bordered Abyssinia to the south, Yakyakistan to the north, and through artificial bridges, Griffonstone to the east.

There were many monarchies within Equestria however, such as Thicket and Diamondia.