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Authorities differ on whether the Lords Spiritual are peers. Some contend that archbishops and diocesan bishops are peers during their tenures in the House of Lords, while others argue that only the Lords Temporal are peers. Debrett's Peerage and Baronetage, for example, unequivocally states, "Diocesan Bishops of England in the Lords are ? peers of the kingdom." On the other hand, the Encyclopædia Britannica of 1911 suggests, "the spiritual lords are not now regarded as peers."
Even during the early years of the Peerage, the position of bishops was unclear. During the reign of King Richard II, the Archbishop of Canterbury declared, "of right and by the custom of the realm of England it belongeth to the Archbishop of Canterbury for the time being as well as others his suffragans, brethren and fellow Bishops, Abbots and Priors and other prelates whatsoever, ? to be present in person in all the King's Parliaments whatsoever as Peers of the Realm." The claim was neither agreed nor disagreed to, however, by Parliament.
The Lords Spiritual at first declared themselves entirely outside the jurisdiction of secular authorities; the question of trial in the House of Lords did not arise. When papal authority was great, the King could do little but admit a lack of jurisdiction over the prelates. Later, however, when the power of the Pope in England was reduced, the Lords Spiritual came under the authority of the secular courts. The jurisdiction of the common courts was clearly established by the time of Henry VIII, who declared himself head of the Church of England in place of the Pope, ending the political power of the Roman Catholic Church in England.
Despite their failure to be tried as temporal peers in the House of Lords, it remained unclear whether the Lords Spiritual were indeed peers. In 1688, the issue arose during the trial of the Seven Bishops?William Sancroft, Archbishop of Canterbury; Sir Jonathan Trelawny, 3rd Baronet, Bishop of Winchester; Thomas Ken, Bishop of Bath and Wells; John Lake, Bishop of Chester; William Lloyd, Bishop of Worcester; Francis Turner, Bishop of Ely and Thomas White, Bishop of Peterborough?by a common jury. The charge was that a petition sent by the Bishops constituted seditious libel; the Bishops argued that they had the right to petition the Sovereign at any time, while the prosecution charged that such a right was only permissible when Parliament was in session (which, at the time of the delivery of the petition, it was not). If the bishops were only Lords of Parliament, and not peers, their right to petition would be vitiated while Parliament was dissolved. Peers, however, were and still are counsellors of the Sovereign whether Parliament is in session or not; therefore, if the bishops were indeed peers, they would be free to send petitions. Since there was no doubt that the petition was actually sent, while the Court still ruled the bishops not guilty, it appears that it was taken for granted that the bishops were counsellors of the Crown.
Nevertheless, the Standing Orders of the House of Lords provide, "Bishops to whom a writ of summons has been issued are not Peers but are Lords of Parliament."