The Kingdom of Ponyland was a constitutional monarchy existing at the time of the Catastrophe. It no longer exists as such, but not a few of its ceremonial nobility reestablished themselves as actual feudal lords during the Dark Age, although they were often forced by pragmatism to accept successful warlords and pretenders as peers.
The Isle of Yore, as part of the Oriental Grand Duchy of Ponyland, has been part of Ponyland since its equine colonization in the Classical Era. Before that, it was posessed by indigeneous boars, who did not have an island-wide state, but were organized on typical lines for non-agricultural gatherers.
Geographically, Ponyland is a large landmass West of the Isle of Yore. Ponyland is distantly East of Equestria, the cultural and political hegemon of Equine civilization at the time of the Catastrophe.