The claim to supreme, final authority within a defined territorial order — the right to make law without appeal to any higher earthly power. The concept in its modern form is the invention of 16th- and 17th-century political theorists wrestling with the collapse of medieval jurisdictional pluralism (pope vs. emperor, church vs. king, town vs. lord) and the wars of religion. Jean Bodin's Six Books of the Commonwealth (1576) gave sovereignty its first systematic statement: a single, undivided, perpetual power to make and unmake law, located in a specific person or body.
Thomas Hobbes's Leviathan radicalized the concept, making sovereignty the precondition of all law, justice, and property — divide it, he argued, and civil war follows. Jean-Jacques Rousseau displaced the locus from king to people ("popular sovereignty") while preserving the logic of indivisibility: the general will, too, must be final and unified. The Peace of Westphalia (1648) consolidated the international-relations corollary — states as sovereigns recognizing each other's territorial supremacy and refusing external interference — producing what is still called the "Westphalian" system.
The 20th century brought the concept under sustained pressure from three directions. Above: international human rights law, the UN Charter, and supranational institutions (especially the EU) constrain what states may do within their borders. Below: claims of indigenous peoples, substate nations, and devolved regions challenge the one-sovereign-per-territory assumption. Across: transnational capital, networked communication, climate, and migration ignore territorial borders in ways sovereigns cannot fully regulate. Hannah Arendt argued already in the 1950s that sovereignty was incompatible with genuine politics, which requires plurality; more recent theorists (Stephen Krasner, Saskia Sassen) have mapped the concept's fragmentation empirically.
Yet sovereignty has not withered away. Brexit, resurgent nationalism, Russian and Chinese appeals to non-interference, and populist campaigns against supranational governance have all been partly fought as reassertions of sovereign prerogative. The concept's obituaries have proved premature.