Known by whom?

In Europe, there was, it is called the Concert of Europe. According to the Wiki page, this period of stability lasted from 1815 until WWI, but most historians agree it ended with the Crimean War (1856-1858).Still, there were several revolutions, other kinds of political upheavel and major social unrest.

Besides, in other parts of the world there was war, in which Western powers were engaged, such as the Opium War.

Sorry, we don't allow throughout history questions. These tend to produce threads which are collections of trivia, not the in-depth discussions about a particular topic we're looking for. If you have a specific question about a historical event or period or person, please feel free to re-compose your question and submit it again.