First of all we need to know about sovereignty. So it is basically the authority to govern a nation or a group of people. It is the true right to exercise power politically, judicially, legislatively, and/or executively over a geographic region, group of people or oneself. Countries acquire sovereignty by the recognition of its people.
Monaco was granted sovereignty in 1861. It is in France and is famous for its yacht lined harbors and upscale casinos.