 Membership was once an entitlement of all hereditary peers, other than those in the peerage of Ireland, but under the House of Lords Act 1999, the right to membership was restricted to 92 hereditary peers.From 2008 to 2020, only one of them was female (Countess of Mar); most hereditary peerages can be inherited only by men.While the House of Commons has a defined number of members, the number of members in the House of Lords is not fixed.