Short answers, pulled from the story.
The Hittite king Hattusili III and the Egyptian pharaoh Ramesses II signed a peace agreement in 1279 BCE. This document stands as one of the earliest recorded international treaties between sovereign polities.
Dutch jurist Hugo Grotius published his seminal work De Jure Belli ac Pacis in 1625. He argued that nations should be governed by natural law rather than force or warfare alone.
Article 38 of the Statute of the International Court of Justice lists treaties and customary international law as primary sources. A treaty requires consent through signature, ratification, acceptance, approval or accession to become binding.
The United Nations General Assembly adopted the Universal Declaration of Human Rights in 1948 following World War II. Eleanor Roosevelt chaired the committee that drafted this document establishing non-binding standards for work housing education and fair trials.
UNCLOS defined territorial sea boundaries at most twelve nautical miles from coastal baselines in 1982. States claim exclusive economic zones stretching up to two hundred nautical miles granting sovereign rights over natural resources.
The International Criminal Court opened its doors following ratification of the Rome Statute in 1998 becoming the first permanent court to prosecute genocide war crimes and aggression. One hundred twenty-three state parties currently recognize its jurisdiction though some nations like the United States refuse participation.