Duchy of Mazovia (Belz): this was a short-lived division of Mazovia which was independent only for the lifetime of its sole ruler between 1446 and 1442.
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Duchy of Mazovia (Belz): this was a short-lived division of Mazovia which was independent only for the lifetime of its sole ruler between 1446 and 1442.
Coverage of the various historical cultures, rulers, and states of Europe

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Investigation reveals King Charles and the late queen’s income from duchies grew sixteenfold during Elizabeth’s reign
King Charles and the late Queen Elizabeth II have received payments equivalent to more than £1bn from two land and property estates that are at the centre of a centuries-old debate over whether their profits should be given to the public instead.
An investigation by the Guardian has established the full scale of income extracted by the royals from the duchies of Lancaster and Cornwall, which run giant portfolios of land and property across England.
The duchies operate as professionally run real estate empires that manage swathes of farmland, hotels, medieval castles, offices, shops and some of London’s prime luxury real estate. They also have substantial investment portfolios, but pay no corporation tax or capital gains tax.
Duchy accounts, held in parliamentary and state archives, reveal how the queen and her first-born son, in his capacity as the Duke of Cornwall, benefited from a huge increase in their revenues from the duchies during her seven-decade reign.
Duchies for the Royal Children
Healthy reminder to all you that I'm a huge history nerd so there'll be a lot of references. Anyways, the headcanon goes like this:
Callisto give each of his kids a duchy on 21st birthday for them to govern. Don't worry about Judith, she gets her own kingdom (probably Delman) to practice run until she becomes empress.
It makes sense politically. I mean it is a bit stupid to only have one duke in an entire empire, who can decide to revolt at any moment and win. And an empire has many different places that need different types for control. (It gives me imperialist/colonialist vibes but that's what the Ioka Empire is all about).
As far as we know, Ioka is still a growing empire and Callisto, as Emperor, needs to solidify his power bases in each region. Duke Eckhart is probs the head aristocrat for the original kingdom before the conquering began and if new territories are being added so would new Dukes to keep status quo. Callisto might have also secretly gotten conquered territories for himself as a personal investment.
It would also solve their inheritance problem. Since Judith would get most of the stuff because it comes with being the eldest and the heir, there wouldn't be much left for the younger children. Unless they get something before Callisto's dead. Duchies also produce a butt-ton of money, so they'll be set for life.
In real life, most Austrian Archdukes (younger sons of the Emperor) who were far from the throne were given territories to govern in place of the Emperor since they were either on the brink of independence or wanted by the empire. They lived in the territories and ruled them however they pleased. Sometimes, they'll be very active in governance or just leave everything to their advisors. Some Archdukes turned their courts into intellectual and artistic powerhouses, some turned their courts into whorehouses and some did both. The point is that they were given independence and did anything they wanted provided they ruled on behalf of the emperor.
Tieflings in Falandar
What the post is about: the treatment of tieflings in different kingdoms as well as their origins.
Origins
Tieflings came to be after the first Demon War. The heroes who fought against the demonic incursion were cursed by the Dukes of Hell to appear more like the demons they slayed making the first tieflings.
Treatment in Falandar
Tieflings are known as the most regal race. Their eyes as varied as the earths gems, their skin a whole chromatic spectrum, their animal features showing their ties to the nature from whence we came and their horns remind us of the demons their for-fathers slew.
Of course this could have gone very differently and it has in some places. The nation of Dragma sees tieflings as a vile corruption, a curse, even if there human ancestors were heroes that held back the demonic hordes, they should have died as heroes instead of baring the vile mark of those they bested. They fear what the corruption could do to people and that their fiendish blood might drive them to evil as it drew the first ruler of Dragma, Ivan the Mad.
Other nations such as the Duchies see Tieflings as a race to be revered but not quite enough to have become the nobility nor the ruling class. The Duchies chose to keep their bloodlines pure of fiendish blood all those years ago.
Then come the Flora Kingdoms in the west, Escia, Gladsia, and Palhosia. Here Tieflings weren’t just honored, they became the Kings and Queens of the land. The Flora kingdoms used to be a loose assortment of houses until the First Demon War United the houses under 3 banners. The Stag of Escia, the Ram of Gladsia, and the Wolf of Palhosia. The rulers of these 3 great houses became Tieflings after the war solidifying a bloodline of warrior Kings and Queens for ages to come.
TL;DR: Tiefling racism exists in some places like Dragma, but the rest of the nations are cool with tieflings and some raise Tieflings as a royal or noble race of people do to their history.
United Duchies of America (Monarchist America)
from /r/vexillology Top comment: The symbolism is the same as the normal US flag except the canton has a version of the Washington Coat of Arms modified to be symmetrical.

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Estelle, Leonore, Alexander and Oscar during the first visits to their duchies. While Estelle's present from her duchy was a fairytale trail in Östergötland, Leonore made first contact with the Horse Heidi which was a present from her duchy Gotland. Alexander became friends with a big wooden duck on a viewpoint named after him in Södermanland and Oscar had some fun on the playground in Skåne.
“The binding was made in Paris between 1550 and 1555 either by Claude de Picques or by Jean Picard.”
“ To fully appreciate the importance of this binding and its relation to Picques we must again turn to "An Essay in the History of Gold-Tooled Bindings" by Herbert P. Horne London 1894. "...we must turn to the books of Charles IX., who succeeded his brother in 1560, not only for a new manner, but, also, for a new style. This style, which was adapted from the medieval device of the' semis,' the repetition of some given figure over a field at regular intervals, continued in use upon the books of the royal libraries, during the following century: and it is in the invention of this style, that French gilding first appears to free itself from the traditions. of Italian Art. A remarkable binding tooled in this way covers a book, which was placed in the library at Fontainebleau, by Katherine de Medicis, in memory of Henri II., and 'which is reproduced by M. Gruel, in his Manuel. The' semis,' with which this book is ornamented, consists in the repetition of two crowned cyphers, the one formed by the C of Charles IX., the other of the K of Katherine repeated and reversed. “
Decorative french finishing, 1500s - duchies: combo geometric + floral/organic (antlers?)
Duchy of Marsi: Marsi again became the seat of a noble family in the fifteenth century, this time for the Italian noble family of Colonna who had already supplied Pope Martin V in 1417-1431.
Coverage of the various historical cultures, rulers, and states of Europe