The United Kingdom constitutional law concerns the governance of the United Kingdom of Great Britain and Northern Ireland. With the oldest continuous political system on Earth, the British constitution is not contained in a single code but principles have emerged over the centuries from statute, case law, political conventions and social consensus. In 1215, Magna Carta required the King to call "common counsel" or Parliament, hold courts in a fixed place, guarantee fair trials, guarantee free movement of people, and free the church from the state; it also enshrined the rights of "common" people to use the land. After the English Civil War and the Glorious Revolution 1688, Parliament won supremacy over the monarch, as well as the church and the courts, and the Bill of Rights 1689 recorded that the "election of members of Parliament ought to be free". The Act of Union 1707 unified England, Wales and Scotland, while Ireland was joined in 1800, but the Republic of Ireland formally separated between 1916 and 1921 through bitter armed conflict. By the Representation of the People (Equal Franchise) Act 1928, almost every adult man and woman was finally entitled to vote for Parliament. The UK was a founding member of the International Labour Organization (ILO), the United Nations, the Commonwealth, the Council of Europe, the European Union, and the World Trade Organization (WTO). The principles of parliamentary sovereignty, the rule of law, democracy and internationalism guide the UK's modern political system.