A sudden change for most part in the constitution of a country in consequence of internal revolt, particularly when a monarchy is superseded by a republic, as in France in 1789, in 1848, and 1870, that in 1830 being merely from one branch of the Bourbon family to another, such as that also in England in 1658. The French Revolution of 1798 is the revolution by pre-eminence, and the years 1848-49 were years of revolutions in Europe.