Your question has a very broad historical scope, and I am sure other historians on this sub-reddit will be able to provide a focused answer on their area of expertise.

In light of this, I would like to give you the following examples of 18th/19th/20th Century outbreaks of unrest that had significant impacts on the countries they happened in.

The first is the tradition of unrest that swept through France in the period immediately prior to the 1792 revolution up until Napoleon crushed an uprising of the mob on 13 Vendémiaire, which in turn helped usher in a new form of revolutionary government called the Directory (led by Napoleon), and ultimately led to Napoleon's rise in power. After the revolution politicians used the mob to cement their power, and like in Rome or Byzantium the mob was used as a blunt instrument to achieve political change. The difference is that with the French mob, especially after the food shortages were resolved and a veneer of political stability was restored after the fall of Robespierre, the military under Napoleon were able to pacify them. Indeed, it was the bread and stability that enabled Napoleon to remain in power until the capture of Paris in 1814 by the Russians.

Both the Boxer Rebellion and the first Russian Revolution in 1905 are examples of the people coming out in an attempt to radically change their government's policies after catastrophic foreign policy decisions. Both governments had attempted to use harsh measures to suppress the mob and urban workforce, and while they were both successful in the short term, neither the Imperial Chinese or Tsarist authorities ever resolved the intrinsic paradoxes of national pride, desire for political reform, and the need for stable national government. Indeed, the April 1917 Russian revolution was sparked by a desire by the urban populace for peace, bread, and better conditions, which escalated because the Tsar failed to read the mood of the people, and the army siding with the mob against the regime.

The final example I would like to use is that of the British working class, who from the late 18th century right through to the coal miner's strike in 1984 were able to exercise their will through increasing unionisation, strikes, and large scale protests. Unlike many European or American governments, the British establishment was very reluctant to turn armed police or soldiers on strikers or demonstrators, though the Peterlook massacre was an exception to this. The British government were acutely aware of how the French revolution started with mass protests and the utilisation of the mob, and the Duke of Wellington famously delayed right up to the last minute before allowing the passage of the 1832 Reform Act, which extended the franchise and cleaned up the political map of the United Kingdom.

There have been other historic moments where the 'mob' have been used, indeed I would go as far as to say that most countries where there has been significant regime change the mob have been used as a blunt instrument against the previous regime. France in 1968 faced significant student riots,, the USA with the Detroit riots in 1967, and Britain in 1984. Berlin in 1989 and Tehran in 1979 are two recent ones where unrest played a significant role in helping the new regime sweep into power.

N.B. In a break of the 25 year rule, Egypt, Syria, Iraq, and Libya have all been examples of unrest/protests leading to regime change (and back again in the case of Egypt).

In summation, I would posit that almost all countries/empires have faced unrest/rioting throughout their history. The usual factors were food/bread shortages, harsh political practices (or a desire for political reform), or a failure in national policy. Often the deciding factor in whether the rioting/protests led to either regime change or a change in political will was the role the armed forces played. If a regime/government had the backing of the military then the government was able to either ignore/suppress or downplay the protests/rioting. On the other hand, if the military sided with the mob/protesters (or was otherwise unable to handle the mob), then the incumbent regime either backed down or was toppled.

Sources:

Napoleon the Great by Andrew Roberts

The Boxer Rebellion: The Dramatic Story of China's War on Foreigners that Shook the World in the Summer of 1900 by Diana Preston

From the Corn Laws to Free Trade: Interests, Ideas, and Institutions in Historical Perspective by Cheryl Schonhardt-bail

Caught in the Revolution: Petrograd, 1917 by Helen Rappaport