Writ in acceleration

A writ in acceleration, commonly called a writ of acceleration, was a type of writ of summons that enabled the eldest son and heir apparent of a peer with multiple peerage titles to attend the British or Irish House of Lords, using one of his father's subsidiary titles. This procedure could be used to lower the average age of the house, and increase the number of capable members in a house that drew on a very small pool of talent (a few dozen families in its early centuries, a few hundred in its later centuries), without increasing the effective size of the peerage and thereby diluting the exclusivity of noble titles.

The procedure of writs of acceleration was introduced by King Edward IV in the mid 15th century. It was a fairly rare occurrence, and only 98 writs of acceleration were issued in over 400 years. The last writ of acceleration was issued in 1992 to the Conservative politician and close political associate of John Major, Robert Gascoyne-Cecil, Viscount Cranborne, the eldest son and heir apparent of the 6th Marquess of Salisbury. He was summoned in his father's junior barony of Baron Cecil of Essendon and not in his courtesy title of Viscount Cranborne. 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.

A writ of acceleration was granted only if the title being accelerated was a subsidiary one, and not the main title, and if the beneficiary of the writ was the heir apparent of the actual holder of the title; thus the elder peer was always at least a viscount. The heir apparent was not always summoned in his courtesy title; rather, almost every person summoned to Parliament by virtue of a writ of acceleration was summoned in one of his father’s baronies. For example, William Cavendish, Marquess of Hartington, heir apparent of William Cavendish, 3rd Duke of Devonshire, was summoned as Baron Cavendish of Hardwick. It was not possible for heirs apparent of peers in the Peerage of Scotland and Peerage of Ireland to be given writs of acceleration after 1707 and 1801, respectively, as holders of titles in these peerages were not automatically guaranteed a seat in the British House of Lords.

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