There are quite a lot! Using "History" of some variety to advance a political agenda is a tried and true strategy in at least medieval Europe. This goes back a long ways; the Aeneid is arguably part of a tradition of pseudo-history, since it tells the story of one of Julius' Caesar's claimed ancestors, and through Aeneas' deeds at the end of the poem, justifies Augustus' position of princeps.

In Scandinavia, my area of training, pseudo-history can be divided into Latin histories, Old Norse saga texts, and genealogies. These overlap extensively, but are all used to advance political agendas. Saxo Grammaticus' Gesta Danorum devotes 9 of its 16 books to pre-Christianization and Denmark's legendary past, including its founding by the mythical king Dan. All of these legends are both enjoyable to read and politically motivated; he combined Classical Latin ideas, such as Amazons, to Norse history to create this narrative leading up to Denmark's pinnacle under its current ruler and Christian order.

Snorri Sturluson's Heimskringla, particularly Ynglinga saga, does the same thing with Norway. Yngvi is another name for the god Freyr, and the Ynglings are his descendants. The "unifier" of Norway, Haraldr harfagri, is one of the Ynglings, and the legitimacy of a claim on the throne of Norway directly or indirectly relied on being able to trace descent back to him. Heimskringla was composed while Snorri was in the good favors of Hákon IV, and so likely was meant to be an "official" history leading up to him. Ynglinga saga includes and is derived from the genealogical poem Ynglingatal, indicating that genealogical information was used to strengthen current political claims since before Christianity took hold in Scandinavia.

Lastly, we have saga evidence. Egils saga is one of the clearest examples. While the authorship is unknown, one proposal is that it is yet another text made by Snorri Sturluson. The reason for this is that, when Egill's father Skalla-Grímr is claiming land in Iceland, the claim he makes is gargantuan. The land is, conveniently, an almost exact match to the center of Snorri's property holdings in Reykholt, near the town of Borgarnes. So, it has been argued that Snorri increased the size of the claim to justify his attempts to buy up all the land in the area; after all, it's his by right from the original settlement of Iceland! Most of the copies of the Icelandic Book of Settlements give Skalla-Grímr a much more reasonable land claim, except one. This one we actually know the authorship, it's by Snorri's nephew Sturla Þórðarson, who inherited Reykholt after Snorri's death. The politics is clear; change the history to justify the claim the Sturlungar were making on the territory in Borgarnes.

Hopefully, someone else will be able to come in and discuss pseudohistory in a different part of the world soon, but I hope that is illustrative for now!