The House of Lords Bill 1998–99 sought to abolish the right of all hereditary peers to sit and vote in the House of Lords, and represented the most significant attempt to reform the House for some years. During the Lords consideration of the Bill, Lord Weatherill moved an amendment to allow 92 hereditary peers to remain as Members of the House. Thus the amendment, which was accepted in both Houses and became part of the House of Lords Act 1999, has become known as the ‘Weatherill amendment’. This Library Note provides a history of the amendment and outlines developments since 1999.