From what I recall Austria Hungary had an ethnic German population of only 23% (in 1911) with the rest being comprised of miscellaneous Bohemians, Slovaks, Hungarians, Croats, Serbs, Ruthenians, Poles and so on. It's actually really surprising how well the empire held together for so long. It managed so well in my opinion because no ethnic group was large enough to impose itself on everyone else, the power of the Austrian authorities to make people speak German (outside the army) for instance was nil and the separate kingdoms under the Austrian crown had their own legislatures which operated in the local language, (the Diet in Hungary had wide ranging powers, other smaller scale local parliaments were also unusually powerful). Added to the fact that adherence to the emperor was a "habit" that was common to all. For instance, none of the royal palaces in Hungary were looted after the Hapsburg left, even though they had no guards. Respect for the authority of the monarchy was pervasive and provided an external locus of loyalty as a counterweight to nationalism, at least to some extent. I think the problem that you are referring to is when a dominant culture comes into contact with a subaltern culture which is incompatible with the values of the dominant, which seeks to integrate. At some point the contradiction becomes conflict. The relative weakness of the ethnic Germans meant that the conflict creating step, integration and the backlash by the minority culture, was largely skipped. Hope this helps.

I would possibly look at the ottoman empire in the height of its power, pre-19th 20th century decline. It's population was vast and multi-cultural, but still had many rights for the minority religions and races. Though I think I read somewhere that they colour coded religions or race by clothing.

One interesting situation was the migration of Jews to the Netherlands around the 16th and 17th centuries, but I'm not quite sure of the ratio of Christians to Jews in the city. While they were constantly persecuted across Europe especially in the Iberian peninsula and in Eastern Europe, they found relative security and freedom in the Netherlands.

Sephardic Jews had often been prohibited from trades because they were denied guild membership and they could not own land, so they developed banking and trading networks. The access to this source of capital, skill, and connections was extremely valuable to the development of the Dutch economy. They were not given the full rights of Christians, but they had more rights than they had in many other places in Europe. Ashkenazi Jews also could live in Amsterdam and other Dutch cities even though it was the Sephardic Jews who provided the initial economic boost. Cities in the 17th century were free to set their own laws for Jews, so some cities like Amsterdam could offer slightly more rights to Jews, so they would settle there and benefit their economy.

It was a type of pragmatic toleration that really helped the Dutch economy and gave more security to the Jewish population who often were ousted from wherever they tried to settle in Europe. "Relative harmony" here would not mean full rights, but rather it was far better than life in many other places. I think it is also important to note that when a city government might grant rights to Jews, the general public and religious community might not have agreed with the concessions.

In the Iberian peninsula they were being forced to convert to Christianity, in Poland maybe 100,000 (estimates are all over the place) Jews died in massacres during the mid 17th century Khmelnytsky Uprising. In many places across Europe they were forced to wear a Star of David or a yellow hat.

I think the really vague estimate for the Jewish portion of the population would be more than 1% less than 10%.

Depends on how you define "large increase", and what are the "aliens". The Indian sub-continent has had many waves of immigrations over the last 4-5 Millenia, usually they have involved periods of conflicts and assimilation. In the last century, the primary identity based conflict has been along religious lines, the biggest expression of which was the creation of Pakistan in 1947.

While many people in India (including Historians from India and abroad) argue that the modern religious conflict in India is a product of British colonial policies of "Divide and Rule" (which does have some merit), conflicts along religious lines in India were actually not that uncommon prior to their arrival as well. (See Aurangzeb the last of the "Great Mughals" and his attempts at suppressing non-Muslims).

As far as good administration helping resolve conflicts go, the name of the 3rd Mughal Ruler Akbar the Great (pretty redundant name as Akbar itself means great) bears mentioning. He ended jiziya (a tax on non-muslims) and made peace with various minor Hindu kingdoms. At the same time, his court was diverse employing many non-muslims in important positions, Raja Todarmal (who overhauled the revenue system of the Mughal Empire by basing taxation rates on economic data from the last ten years) and Birbal being the most famous. (stories of Akbar and Birbal are popular entertainment even today, though they don't necessarily have a basis in history).

Though Akbar's policies didn't end Hindu-Muslim conflict in India (There was even conflict between his Muslim and Hindu advisers rooted in distrust of the other religion), the country benefited from his enlightened stand on religion and made Akbar one of the richest and most powerful rulers in the world.

There wasn't much trouble with the French who remained in Canada when it passed into British hands following the Seven Years War. Even with Pontiac's War providing them an opportunity to avenge the fall of Canada few took up arms with the Native Americans.

Now part of this is that they didn't really move, the border moved on them, but they were living in a land that was having an increasing amount of contact with the new "owners."