Short answers, pulled from the story.
Thomas Hobbes published the book Leviathan in 1651. The work depicted the sovereign as a giant man made of thousands of tiny people to illustrate that the state is a collective creation of its citizens.
Jean Bodin, a French jurist, began to articulate the theory of sovereignty in the late 1500s. He argued that the state must have a supreme power that was absolute and perpetual to prevent chaos and instability.
The Peace of Westphalia was signed in 1648 to end the Thirty Years' War. This treaty established the principle of territorial sovereignty, asserting that each state had the right to govern its own affairs without interference from other states.
The United Nations adopted the Universal Declaration of Human Rights in 1948. This declaration established that certain rights were inherent to all human beings regardless of their nationality and challenged the absolute nature of state sovereignty.
The Responsibility to Protect agreement was adopted in 2005. This principle authorized the United Nations to take action to avert a humanitarian catastrophe within a state when that state's government cannot or will not act.