The United States of Greater Austria is an obvious answer,
as is a surviving Ottoman Empire.
German Empire Mitteleuropa, as well. So basically, keep the Central Powers alive.
Avert WW2 or have the French government flee to Africa after defeat by the Kaiser, and you can create a Francophone African federation.
And while you're at it, add the Greater East-Asian Co-Prosperity Sphere, although that's likely to lead to a terrible time for all non-Japanese within its borders.
Perhaps a communist/Christian socialist federation consisting of several Latin American countries?
There are of course two existing ethnic federations, India and Indonesia. The Philippines might count, too, depending on what you consider an ethnic federation.
Brazil annexing Uruguay in the Cisplatine War (and perhaps pushing further into Argentina or Paraguay during the 19th century!) would result in a dual Spanish and Portuguese speaking Brazil, with the addition of the Guarani language if it includes Paraguay. It would have important repercussions in terms of exacerbating tensions between South and North Brazil which are already considerable in OTL.
The United States of Greater Austria is an obvious answer, as is a surviving Ottoman Empire. German Empire Mitteleuropa, as well. So basically, keep the Central Powers alive.
Avert WW2 or have the French government flee to Africa after defeat by the Kaiser, and you can create a Francophone African federation.
And while you're at it, add the Greater East-Asian Co-Prosperity Sphere, although that's likely to lead to a terrible time for all non-Japanese within its borders.
Perhaps a communist/Christian socialist federation consisting of several Latin American countries?
There are of course two existing ethnic federations, India and Indonesia. The Philippines might count, too, depending on what you consider an ethnic federation.
What were the exact monarchies involved?There was a plan around 1872 to reform the Ottoman Empire into a federation of monarchies, loosely inspired by the German Empire. This plan was crafted and supported by some powerful figures (the Grand Vizier), and it also had the approval of some of the "Great Powers"; so while it went nowhere in OTL, there were ways it could have been made to work.
Now, whether this entity would qualify as an "ethnic" federation or not is hard to say.
I don't see it as clearly, New France had a population of 70,000 when Britain took over and you still have French speakers in Canada to this day.Considering Uruguay had barely over 100,000 people during the Cisplatine War, I think the region would be solidly Portuguese speaking, as long as Brazil makes immigrants and others speak Portuguese.
What were the exact monarchies involved?
OK. Also, though, why exactly did this plan fail?Romania, Serbia, Egypt and Tunisia; maybe Crete and Lebanon, and one or two other Arabian entities. With an earlier PoD, Circassia, Mingrelia and/or Montenegro might have also been included.
OK. Also, though, why exactly did this plan fail?