Hereditary peer

The hereditary peers form part of the peerage in the United Kingdom. As of 2020 there are 814 hereditary peers: 31 dukes (including 7 royal dukes), 34 marquesses, 193 earls, 112 viscounts, and 444 barons.
From 1963 to 1999, all non-Irish peers were entitled to sit in the House of Lords, but since the House of Lords Act 1999 was passed, only 92 are permitted to do so, unless they are also life peers. 
Peers are called to the House of Lords with a writ of summons.