Distinguish between external sovereignty and internal sovereignty

Sovereignty is the principle of supreme and unquestionable authority, reflected in the claim by the state to be the sole author of laws within its territory. 
Definition of external vs. internal sovereignty
Internal sovereignty refers to the relationship between a sovereign power and its subjects – it refers to the location of the supreme authority within the state. In the UK, for example, internal sovereignty (supposedly) resides within Parliament, reflected in the constitutional principle of parliamentary sovereignty.By contrast external sovereignty refers to the capacity of the state to act independently and autonomously on the world stage. This is what is sometimes called ‘state sovereignty’ or ‘national sovereignty’, and implies that states are legally equal and that the territorial integrity and political independence of a state is inviolable.
The root of the legitimacy
Claims of legitimacy within internal sovereignty usually refer to divine rights of monarchs, or more commonly, a social contract with its people, in which the sovereign body has been elected. For example, legitimacy of Parliament stems from democratic elections. In the past, the King or Queen had sovereignty when legitimacy came from the divine rights of monarchs.By contrast, claims of legitimacy within external sovereignty usually refer to states’ standing on the international stage. In the post-Westphalian world, territorial integrity is meant to be respected, and states are considered legally equal. Nowadays, states’ legitimacy in external sovereignty usually comes from a UN recognition.
Challenges to sovereignty
 External sovereignty comes under challenge in a different way to internal sovereignty.With the increasing human rights international legal structure, external state sovereignty has come under attack. A notable example is the challenge from humanitarian intervention from the 1990s and the notion of The Responsibility to Protect (R2P) adopted by the UN General Assembly in 2005 – both question the viability of state borders (mind you this is constantly challenged by great powers, most recently in the Crimea). Similarly, internal sovereignty has been undermined by economic globalisation. The global economic crash from 2008 showed how powerless governments are to resist the effects of a collapse in a globally interlocking economy.  Some states like Ireland and Greece effectively had to surrender their internal sovereignty to the IMF and ECB.