The first women in the House of Lords took their seats in 1958, forty years after women were granted the right to stand as MPs in the House of Commons. These were life peeresses appointed by the Prime Minister, although countesses had appeared in mediaeval times. 
 Female hereditary peers were able to sit in the Lords from 1963. Female Church of England bishops have been sitting as Lords Spiritual since 2015, although abbesses had appeared in mediaeval times.
 As of December 2022, women make up about 29 per cent of the members of the Lords, which compares with about 35 per cent of the members of the Commons. 
 The exclusion of women from Parliament is relatively modern.  Gurdon, in his "Antiquities of Parliament," says that "ladies of birth and quality sat in council with the Saxon Witas". In Wighfred's great council at Becconfeld in A.D. 694, abbesses sat and deliberated.  Five of them signed decrees of that council along with the king, bishops, and nobles. 
 During the reigns of Henry III and Edward I, four abbesses, were summoned to Parliament.  These were the abbesses of Shaftesbury, Barking, Winchester, and Wilton.
 In a ceremony borrowed from Marguerite of Angouleme's creation as Duke of Berry in 1517, King Henry VIII made Anne Boleyn Marquis of Pembroke in her own right.  This entitled her to sit in the House of Lords.
 When a peer had no sons, but only daughters they were co-heiresses and could be countesses in their own right.  In the 35th year of Edward III's reign countesses were summoned to Parliament by writ: Mary, Countess of Norfolk; Eleanor, Countess of Ormonde; Anne, Lady de Spenser; Phillippe, Countess of March; Joanna, Lady Fitzwalter; Agneta and Mary, Countesses of Pembroke; Margaret, Lady de Roos; Matilda, Countess of Oxford,; and Catherine, Countess of Athol.   Although peerages had long been created for and inherited by women, peeresses were later excluded from the House of Lords.
 The very first woman, in modern times, to address the House of Lords was a witness, not a peer: Mrs Elizabeth Robinson (née Hastings; 1695–1779)[better source needed] from Gibraltar, gave evidence and testimony about slave trafficking.[failed verification] 
 The Life Peerages Act 1958 made possible the creation of peerages for life, in order to address the declining number of active members. Women were immediately eligible and four were among the first life peers appointed, including Baroness Wootton of Abinger, who was the first woman to be appointed, and Baroness Swanborough, who was the first to take her seat. However, hereditary peeresses continued to be excluded until the passage of the Peerage Act 1963; the first to take her seat was Baroness Strange of Knokin.
 The first female chief whip was Baroness Llewelyn-Davies of Hastoe in 1973. Janet Young, Baroness Young was the first woman leader of the House of Lords in 1981. Brenda Hale, Baroness Hale of Richmond became the first female Law Lord in 2004.
 Since the passage of the House of Lords Act 1999, hereditary peeresses remain eligible for election to the Upper House. Five were elected in 1999 among the 92 hereditary peers who continued to sit. Of these, three have since died, and the other two retired in 2014 and 2020. (Margaret of Mar, 31st Countess of Mar was the last remaining female hereditary peer in the Lords when she retired). All  of these were replaced by male hereditary peers in by-elections.
 Following a change to the law in 2014 to allow women to be ordained bishops, the Lords Spiritual (Women) Act 2015 was passed, which provides that whenever a vacancy arises among the Lords Spiritual during the ten years following the Act coming into force, the vacancy has to be filled by a woman, if one is eligible. This does not apply to the five bishops who sit by right (one of whom is female, as of 2020).
 In 2015, Rachel Treweek, Bishop of Gloucester, became the first woman to sit as a Lord Spiritual in the House of Lords due to the Act. As of 2020, five women bishops sit as Lord Spirituals in the House of Lords.
 Compared with the House of Commons, women make up slightly fewer of the total members of the Lords: 220 out of 650 (34 per cent) members of the Commons were women as of October 2020, up from 32 per cent after the 2017 General Election.