The procedure of writs of acceleration was introduced by King Edward IV in the mid 15th century. It was a fairly rare occurrence, and in over 400 years only 98 writs of acceleration were issued. The last such writ of acceleration was issued in 1992 to the Conservative politician and close political associate of John Major, Viscount Cranborne, the eldest son and heir apparent of the 6th Marquess of Salisbury. He was summoned as Baron Cecil of Essendon, and not as Viscount Cranborne, the title he used by courtesy. The procedure of writs of acceleration was abolished through the House of Lords Act 1999, along with the automatic right of hereditary peers to sit in the House of Lords.