The UK's constitution is not written in one single document like many other countries' are. In fact, the UK's constitution is not completely written down at all. Some of it can be found in writing, starting with the Magna Carta of 1215 and the Bill of Rights Act 1689 and including more modern Acts of Parliament. Other parts of it are considered common law and are made up of the decisions of judges over many hundreds of years in a system called legal or judicial precedence. Because of this, some people say that the United Kingdom has a "de facto" or "unwritten" constitution.