Welsh law is the primary and secondary legislation generated by the National Assembly for Wales, according to devolved authority granted in the Government of Wales Act 2006. Each piece of Welsh legislation is known as an Act of the Assembly. The first Assembly legislation to be officially proposed was called the NHS Redress (Wales) Measure 2008. These powers have been effective since May 2007. It is the first time in almost 500 years that Wales has had its own laws, since Cyfraith Hywel, a version of Celtic law, was abolished and replaced by English law through the Laws in Wales Acts, passed between 1535 and 1542 by King Henry VIII.
Both the Government of Wales Act 1998 and the Government of Wales Act 2006 set out areas of devolved responsibility for the National Assembly for Wales (commonly known as the Welsh Assembly). The 2006 granted the Assembly legislative competence to make laws (known as Assembly Measures) in clearly defined "matters". In order to draft laws that are part of its area of responsibility, but where the powers of legislative competence have not been devolved to it, the Welsh Assembly could request these powers using a Legislative Competency Order or they can receive the transfer of power and the right to make laws through parliamentary bills.