The Triple Principality, Three Princes of the River, is a union of three nations; Hiraacaland, Ruptareland and Sahnishland, spread over a considerable stretch of the Missouri River (OTL Central North & South Dakota). To the West they are bordered by the Lakota Federation, the East by Isanyathimark and to the North by Nakotaland.
They all use the Three Principality Warux (Rabbit) (TPW) as their currency.
As Hiraaca, Ruptare and Sahnish are mutually unintelligible most inhabitants use Lakota as a lingua franca.
The three tribes of Hiraaca, Ruptare and Sahnish were settled along the upper reaches of the Missouri river by the time of the Norse arrival. Unlike their neighbours they were not nomadic, instead relying on settled agriculture for subsistence, trading with their larger neighbours for meat and furs.
The largely peaceful existence changed with the 'movement'. During the expansion of the Erie and the Aniwunwiyan Empire during the 1200s there was a mass displacement of tribes from the Fraeburt Votnum (OTL Great Lakes) area. This caused friction between the old residents and the new arrivals from the East.
The future Three Principalities were overrun by Lakota and Isanyathi tribes during this influx and suffered severe famines and years of disease as a result. The Black Death repeatedly crossed the plains devastating the close knit tribal families long after it had declined in Vinland and the East.
During the Mexica-Leifia and Mexica-Kalmar Wars the Three Principalities were considered vassal states to the Lakota. It was only after the 'long march' in 1781 during the 2nd Mexica-Kalmar War, driving Mexica troops back south from their outposts in Cree territory, that they were recognised as independent.
Since then, the Principalities have grown slowly. It is hoped that once a spur of the Trans-Liefia Railway is completed from Nakotaland through the Three Principalities that their fortunes will rise.
The most northerly of the Principalities is Hiraacaland. It is also the smallest by population and most of that is concentrated in its capital Menoken.
It is currently ruled by Princess Maxidiwiac.
It was Hiraaca scouts who helped Greenlanders travel across Leifia to the Roasjoinn in 1282 and for many years remained the middlemen of choice between the tribes of the West and traders operating around the Fraeburt Votnum.
'Hiraacing' has become another word for exploring in Vinlandic. The main Greenland to Keewatin ferry is named 'Hiraaca' .
Ruptareland is the central principality. The Union's government is held in its capital Wishek. Though each of the principalities has its own small council parliament all decisions are only legal once passed through the central Union chamber.
Prince Matotohpe is distantly related to the Erikssons of Álengiamark and has been instrumental at getting the Trans-Leifia Railway extended into the Three Principalities.
Oddly, many Vinlandic scholars were once convinced that the Ruptare were actually a displaced Celtic tribe, mainly due to their language and lighter skin colour compared to their neighbours. A few Cornish-Vinlanders travelled westwards to explore this idea in the 1830s and settled in the region, adding a Celtic trait to some of the small communities.
The most southerly of the Three Principalities, Sahnishland is also the most populated.
The capital Onaka was known by medieval travellers as the 'Gateway to the West' and was their usual resting point before tackling the plains and mountains beyond. As a result of the large concentration of wealth in the city mercenaries from Ruptareland and Hiraacaland were often employed to deter raids from their neighbours. The close collaboration between the three nations in policing, housing and feeding the travellers led, indirectly, to the current union.