The oldest baronetcies affected are: –
English - Monson (1611); Musgrave (1611); Bagot (1627)
Scottish - Johnston (1626); Sinclair-Lockhart (1636)
The full list (ie those where the youngest heir was born before 1 January 1976) is as follows with date of birth of the youngest heir and with an asterisk where the youngest heir is the baronet himself (as per the Debretts article) - and I have listed them by date of birth of the youngest heir, starting with the oldest, so they are in anticipated order of extinction, rather than alphabetically :-
MOON (UK 1887) b 1919; OPPENHEIMER (UK 1921) b 1924*; FORWOOD (UK 1895) b 1925*; STEWART (UK 1960) b 1925*; BERNARD (UK 1954) b 1926*; CAMPBELL (UK 1808) b 1927*; BLACK (UK 1922) b 1929*; GROVE (UK 1874) b 1930; GORDON (NS 1706) b 1932*; LEVER (UK 1911) b 1932*; MOWBRAY (UK 1880) b 1932*; LATHAM (UK 1919) b 1934*; BANNERMAN (NS 1682) b 1935*; BLAKER (UK 1919) b 1935*; CUNINGHAME (NS 1672) b 1935*; HAY (NS 1663) b 1935*; LEES (UK 1937) b 1935*; LEIGHTON (E 1693) b 1935*; CLIFFORD (UK 1887) b 1936; COTT (E 1694) b 1936*; CRAUFORD (GB 1781) b 1937*; LAWRENCE (UK 1858) b 1937* Baron Lawrence; DILLWYN-VENABLES-LLEWELYN (UK 1890) b 1938*; GRAHAM (UK 1964) b 1938*; DE LA BERE (UK 1953) b 1939; DUNNING (UK 1930) b 1939*; LYELL (UK 1894) b 1939* Baron Lyell; WALSHAM (UK 1831) b 1939*; WATSON (UK 1895) b 1939*; LINDSAY-HOGG (UK 1905) b 1940*; PHILLIPS (UK 1912) b 1940*; WHITE (UK 1937) b 1940*; ASKE (UK 1922) b 1941*; GOUGH (UK 1842) b 1941* Viscount Gough; MACKESON (UK 1954) b 1941*; PIGOTT-BROWN (UK 1903) b 1941*; FAGGE (E 1660) b 1942*; SYNGE (UK 1801) b 1942* may become dormant; FFOLKES (GB 1774) b 1943*; MAXWELL (NS 1681) b 1943* will probably become dormant; PEARSON (UK 1964) b 1943*; ALBU (UK 1912) b 1944*; BAGOT ( E 1627) b 1944*; CRAIG (UK 1918) b 1944* Viscount Craigavon; FAYRER (UK 1896) b 1944*; MEYER (UK 1910) b 1944*; OHLSON (UK 1920) b 1944; TWISLETON-WYKEHAM-FIENNES (UK 1916) b 1944*; HARDY (UK 1876) b 1945*; BOULTON (UK 1944) b 1946*; CARDEN (UK 1887) b 1946*; HENNIKER (UK 1813) b 1946*; JACKSON (UK 1902) b 1946; SLADE (UK 1831) b 1946*; STRONGE (UK 1803) b 1946*; MEDLYCOTT (UK 1808) b 1947*; MYNORS (UK 1964) b 1947*; STRACHEY (UK 1801) b 1947*; WILKINSON (UK 1941) b 1947*; HORNE (UK 1929) b 1948*; MOND (UK 1910) b 1948* Baron Melchett; PRESCOTT (UK 1938) b 1948*; RHODES (UK 1919) b 1948; VERNEY (UK 1946) b 1948; BOWATER (UK 1914) b 1949*; CROFT (UK 1924) b 1949* Baron Croft; PROBY (UK 1952) b 1949*; ROBINSON (UK 1908) b 1949*; FOWKE (UK 1814) b 1950*; RIPLEY (UK 1880) b 1950*; WRIXON-BECHER (UK 1831) b 1950*; MARLING (UK 1882) b 1951*; MUSGRAVE (E 1611) b 1951; NUGENT (UK 1831) b 1951; MACKENZIE (UK 1890) b 1952; STUART TAYLOR (UK 1917) b 1952*; BANBURY (UK 1903) b 1953* Baron Banbury of Southam; EWART (UK 1887) b 1953*; MILES (UK 1859) b 1953*; BURNETT (UK 1913) b 1954; BURTON –CHADWICK (UK 1935) b 1954*; DORMAN (UK 1923) b 1954*; FISON (UK 1905) b 1954*; TUCK (UK 1910) b 1954; FREEMAN (UK 1945) b 1955*; MOORE (UK 1932) b 1955; PILDITCH (UK 1929) b 1955*; SMITH (UK 1947) b 1955*; D’OYLEY (E 1663) b 1956*; FFRENCH (I 1779) b 1956* Baron ffrench; MILLS (UK 1953) b 1956* Viscount Mills; SAUMAREZ (UK 1801) b 1956 Baron de Saumarez; HANHAM (E 1667) b 1957*; DAWSON (UK 1920) b 1957*; FORBES (UK 1823) b 1957*; HENRY (UK 1923) b 1957*; MILLS (UK 1921) b 1957; SEAGER (UK 1952) b 1957 Baron Leighton of St Mellons; OSBORN (E 1662) b 1958*; CROSSLEY (UK 1909) b 1958*; ELPHINSTONE (UK 1816) b 1958; CROFT (UK 1818) b 1959*; MACGREGOR (UK 1828) b 1959*; MACLEOD (UK 1924) b 1959; COGHILL (GB 1778) b 1960*; DUNTZE (GB 1774) b 1960*; AUSTIN (UK 1894) b 1960; COOPER (UK 1905) b 1960*; NIVISON (UK 1914) b 1960* Baron Glendyne; STEWART-CLARK (UK 1918) b 1960; THOMAS (E 1694) b 1961*; HALL (UK 1919) b 1961; TRITTON (UK 1905) b 1961*; MONSON (E 1611) b 1962 Baron Monson; SOUTHWELL (I 1662) b 1962 Viscount Southwell; BOORD (UK 1896) b 1962; KEYES (UK 1919) b 1962 Baron Keyes; LEY (UK 1905) b 1962; ACKROYD (UK 1956) b 1964; FRANK (UK 1920) b 1964*; GREEN-PRICE (UK 1874) b 1964; ROBERTS (UK 1809) b 1964; JOHNSTON (NS 1626) b 1965; BRAIN (UK 1954) b 1965 Baron Brain; HALL (UK 1923) b 1965; JENKS (UK 1932) b 1965; MAY (UK 1931) b 1965* Baron May; AINSWORTH (UK 1917) b 1966; BOYLE (UK 1904) b 1966; CUNLIFFE-OWEN (UK 1920) b 1966*; EVANS (UK 1920) b 1966; SCOTT (UK 1913) b 1966; TRUSCOTT (UK 1909) b 1966*; WEDGWOOD (UK 1942) b 1966; TENNYSON-D’EYNCOURT (UK 1930) b 1967*; EDGE (UK 1937) b 1968; LAWSON (UK 1892) b 1968* Baron Burnham; RENWICK (UK 1927) b 1968 Baron Renwick; ROSE (UK 1874) b 1968; STOTT (UK 1920) b 1968; RANCHHODLAL (CHINUBHAI) (UK 1913) b 1969; WATSON (UK 1866) b 1969; BUCKWORH-HERNE-SOAME (E 1697) b 1970*; AGNEW-SOMERVILLE (UK 1957) b 1970*; ALEXANDER (UK 1921) b 1970; DAVIS (UK 1946) b 1970; GOOCH (UK 1866) b 1970; STANIER (UK 1917) b 1970; MACKENZIE (NS 1703) b 1971; GRATTAN-BELLEW (UK 1838) b 1971; LAWRENCE-JONES (UK 1831) b 1971; SHAKESPEARE (UK 1942) b 1971; ALLEYNE (GB 1769) b 1972; HARRISON (UK 1922) b 1972; HOUSTON-BOSWALL (UK 1836) b 1972; LACY (UK 1921) b 1972; SINCLAIR-LOCKHART (NS 1636) b 1973; ROBINSON (E 1660) b 1973; HILL (UK 1917) b 1973; NELSON (UK 1955) b 1973* Baron Nelson of Stafford; PRIMROSE (UK 1903) b 1973; SHARP (UK 1920) b 1973; CUST (E 1677) b 1974 Baron Brownlow; LEITH-BUCHANAN (GB 1775) b 1974*; BRISCO (GB 1782) b 1974; BROMHEAD (UK 1806) b 1974; COCKBURN-CAMPBELL (UK 1821) b 1974; LISTER-KAYE (UK 1812) b 1974; HERON-MAXWELL (NS 1683) b 1975; CAREW (E 1661) b 1975; BADEN-POWELL (UK 1922) b 1975 Baron Baden-Powell; BLENNERHASSETT (UK 1809) b 1975; BURBIDGE (UK 1916) b 1975; NEWSON-SMITH (UK 1944) b 1975; ROBERTSON (UK 1919) b 1975* Baron Robertson of Oakridge
Obviously this information is only as good as the information in the standard peerage books supplemented by information on blogs and websites such as this.
In Category 2 the breakdown is E – 17; NS – 15; I – 5; GB – 16; UK – 162 with Dunbar (NS 1700) possibly becoming dormant rather than extinct
Oldest baronetcies in this Category are:-
English – de Hoghton (1611); St John (1611) Viscount Bolingbroke and St John; Dormer (1615) Baron Dormer; Berney (1620); Ashley-Cooper (1622) Earl of Shaftesbury; Sebright (1626)
Scottish – Napier (1627); Sinclair (1631) Earl of Caithness; Bingham (1634) Earl of Lucan; Milborne-Swinnerton-Pilkington (1635)
The following may not actually be within this category as there are heirs whose dates of birth (according to latest Debretts) are unknown:-
Dormer (E 1615); Courtenay (I 1644) Earl of Devon; Rashleigh (UK 1831); Havelock-Allen (UK 1858); Imber-Terry (UK 1917)
The full list in this Category (ie where there is no or only one heir under 35 ie born after 31 December 1981) is:-
DICK-LAUDER (NS 1690) b 1976; CHAYTOR (UK 1831) b 1976; COCHRANE (UK 1903) b 1976; RENSHAW (UK 1903) b 1976; ROYDEN (UK 1905) b 1976; NORTON-GRIFFITHS (UK 1922) b 1976; NAPIER (NS 1627) b 1977; CHETWYND (GB 1795) b 1977; KELLETT (UK 1801) b 1977; COUPER (UK 1841) b 1977*; WALKER (UK 1906) b 1977*; LYNCH-ROBINSON (UK 1920) b 1977; PRYKE (UK 1926) b 1977; BUZZARD (UK 1929) b 1977; SEBRIGHT (E 1626) b 1978*; TROLLOPE (E 1642) b 1978; ABDY (UK 1850) b 1978*; GREEN (UK 1886) b 1978; DURAND (UK 1892) b 1978; EVANS-TIPPING (UK 1913) b 1978; VASSAR-SMITH (UK 1917) b 1978; HANSON (UK 1918) b 1978; BINGHAM (NS 1634) b 1979 Earl of Lucan; HEATHCOTE (GB 1733) b 1979; STRACEY (UK 1818) b 1979; LAWRENCE (UK 1858) b 1979; EDWARDS (UK 1866) b 1979; WATERLOW (UK 1873) b 1979; DE HOGHTON (E 1611) b 1980; ST JOHN (E 1611) b 1980 Viscount Bolingbroke and St John; BURKE (I 1797) b 1980; ROCHE (UK 1838) b 1980; TUPPER (UK 1888) b 1980; GOODHART (UK 1911) b 1980; JACKSON (UK 1913) b 1980; HOOD (UK 1922) b 1980; PLATT (UK 1959) b 1980; WALKER-SMITH (UK 1960) b 1980; SINCLAIR (NS 1631) b 1981 Earl of Caithness; SINCLAIR (NS 1704) b 1981; SHAKERLEY (UK 1838) b 1981; PHILLIMORE (UK 1881) b 1981 Baron Phillimore; PALMER (UK 1886) b 1981; GLIBEY (UK 1893) b 1981; KNILL (UK 1893) b 1981; ARTHUR (UK 1903) b 1981 Baron Glenarthur; LYLE (UK 1929) b 1981; VINCENT (UK 1936) b 1981; ROPNER (UK 1952) b 1981*; SHUCKBURGH (E 1660) b 1982; BLUNDEN (I 1766) b 1982; SHIFFNER (UK 1818) b 1982; SALT (UK 1869) b 1982; KEARLEY (UK 1908) b 1982 Viscount Devonport; MACREADY (UK 1923) b 1982; MACPHERSON (UK 1933) b 1982 Baron Strathcarron; GROTRIAN (UK 1934) b 1982; YOUNG (UK 1945) b 1982; DUNBAR (NS 1694) b 1983; STAMER (UK 1809) b 1983; LEA (UK 1892) b 1983; GOULDING (UK 1904) b 1983; RALLI (UK 1912) b 1983; BROADBRIDGE (UK 1937) b 1983 Baron Broadbridge; OAKES (UK 1939) b 1983; WHITMORE (UK 1954) b 1983; RODGERS (UK 1964) b 1983; FRANKLAND (E 1660) b 1984 Baron Zouche; JENKINSON (E 1661) b 1984; NOBLE (UK 1923) b 1984; DALRYMPLE-WHITE (UK 1926) b 1984; O’NEILL (UK 1929) b 1984 Baron Rathcavan; WHITAKER (UK 1936) b 1984; GRAHAM (GB 1783) b 1985; SIDNEY (UK 1806) b 1985 Viscount de L’Isle; LAWRENCE (UK 1867) b 1985; RENALS (UK 1895) b 1985; REDWOOD (UK 1911) b 1985; IMBER-TERRY (UK 1917) b 1985; MILNE-WATSON (UK 1937) b 1985; ONSLOW (GB 1797) b 1986; DEANE (I 1710) b 1986 Baron Muskerry; JEJEEBHOY (UK 1856) b 1986; MILNE COATES (UK 1911) b 1986; YOUNGER (UK 1911) b 1986; FRASER (UK 1943) b 1986; ROSE (UK 1872/1909) b 1986; BERNEY (E 1620) b 1987; MURRAY (NS 1673) b 1987; WRAXALL (UK 1813) b 1987; LESLIE (UK 1876) b 1987; WHITE (UK 1904) b 1987; BRUNTON (UK 1908) b 1987; KING (UK 1815) b 1988; SHAW (UK 1821) b 1988; PAUNCEFOOT-DUNCOMBE (UK 1859) b 1988; TREVELYAN (UK 1874) b 1988; NIXON (UK 1906) b 1988; HOWARD (UK 1955) b 1988; MUIR MACKENZIE (UK 1805) b 1989; THOMPSON (UK 1890) b 1989; NEWTON (UK 1900) b 1989; ROBERTS (UK 1919) b 1989; POWER (UK 1924) b 1989; GILLETT (UK 1959) b 1989; JEPHCOTT (UK 1962) b 1989; THATCHER (UK 1991) b 1989; SPENCER-SMITH (UK 1804) b 1990; PRESTON (UK 1815) b 1990; DU CROS (UK 1916) b 1990; MARSDEN (UK 1924) b 1990*; DAVSON (UK 1927) b 1990; TOUCHE (UK 1962) b 1990; ASTLEY (E 1660) b 1991 Baron Hastings; DILKE (UK 1862) b 1991; BROOKE (UK 1903) b 1991; BROOKE (UK 1919) b 1991; BIRKMYRE (UK 1921) b 1991; HAWKINS (GB 1778) b 1992; SHERSTON-BAKER (GB 1796) b 1992; HOULDSWORTH (UK 1887) b 1992; LEIGH (UK 1918) b 1992; GUNSTON (UK 1938) b 1992; MILBORNE-SWINNERTON-PILKINGTON (NS 1635) b 1993; HOLDER (UK 1898) b 1993; STUDD (UK 1929) b 1993; LANGHAM (E 1660) b 1994; HAVELOCK-ALLEN (UK 1858) b 1994; PAGET (UK 1871) b 1994; BUCHANAN-JARDINE (UK 1885) b 1994; PAGET (UK 1886) b 1994; HARMSWORTH (UK 1922) b 1994; MCLEOD (UK 1925) b 1994; DORMER (E 1615) b 1995 Baron Dormer; ELTON (GB 1717) b 1995; DARELL (GB 1795) b 1995; DAUBENY DE MOLEYNS (I 1797) b 1995 Baron Ventry; DUNBAR (NS 1698) b 1995; PETIT (UK 1890) b 1995; BIRKIN (UK 1905) b 1995; EDMONSTONE (GB 1774) b 1996; OAKSHOTT (UK 1959) b 1996; LAKE (GB 1711) b 1997; CHOLMELEY (UK 1806) b 1997; RASHLEIGH (UK 1831) b 1997; MORRISON-LOW (UK 1908) b 1997; BOWYER (UK 1933) b 1997 Baron Denham; SETON (NS 1683) b 1998; SULLIVAN (UK 1804) b 1998; GREY (UK 1814) b 1998; HAGART-ALEXANDER (UK 1886) b 1998; HUTCHISON (UK 1956) b 1998; LAMBERT (GB 1711) b 1999; BAKER-WILBRAHAM (GB 1776) b 1999; BAZLEY (UK 1869) b 1999; VIVIAN (UK 1882) b 1999 Baron Swansea; LUCAS-TOOTH (UK 1920) b 1999; ROSS (UK 1960) b 1999; SETON (NS 1663) b 2000; CAMPBELL (UK 1831) b 2000; GULL (UK 1872) b 2000; COATS (UK 1905) b 2000; LACON (UK 1818) b 2001; PRITCHARD-JONES (UK 1910) b 2001; ESPLEN (UK 1921) b 2001; BENNETT (UK 1929) b 2001; FINLAY (UK 1946) b 2001; WOMBWELL (GB 1778) b 2002; PRINGLE (NS 1683) b 2002 disputed; O’CONNELL (UK 1869) b 2003; CHITTY (UK 1924) b 2003; STUART (E 1660) b 2004; SITWELL (UK 1808) b 2004; BARRY (UK 1899) b 2004; PETO (UK 1927) b 2004; PAKINGTON (UK 1846) b 2005 Baron Hampton; GUINNESS (UK 1867) b 2005; BROADBENT (UK 1893) b 2005; DRYDEN (GB 1733) b after 2005; DRYDEN (GB 1795) b after 2005; WHELER (E 1660) b 2006; HARTWELL (UK 1805) b 2006; THOMPSON (UK 1806) b 2006; BAIRD (UK 1809) b 2006; BLYTH (UK 1895) b 2006 Baron Blyth; MITCHELL-THOMSON (UK 1900) b 2006 Baron Selsdon; HORSBRUGH-PORTER (UK 1902) b 2006; SANDERSON (UK 1920) b 2006; AYKROYD (UK 1929) b 2006; SAMUEL (UK 1898) b 2007; RYCROFT (GB 1784) b 2008; PIGOTT (UK 1808) b 2008; HODGE (UK 1921) b 2008; STOREY (UK 1960) b 2008; COURTENAY (I 1644) b 2009 Earl of Devon; HAMILTON (NS 1646) b 2009; HALL (NS 1687) b 2009; SMITH (UK 1897) b 2009; THOMPSON (UK 1963) b 2009; FITZGERALD (UK 1903) b 2010; HARVEY (UK 1933) b 2010; WELCH (UK 1957) b 2010; BARBER (UK 1960) b 2010; DUDLEY-WILLIAMS (UK 1964) b 2010; ASHLEY-COOPER (E 1622) b 2011 Earl of Shaftesbury; BAILLIE (UK 1823) b 2011; WILLIAMSON (UK 1909) b 2011 Baron Forres; DUNBAR (NS 1700) b 2011 may become dormant; PALMER (E 1660) b 2012; ASHBURNHAM (E 1661) b 2013; BURDETT (E 1665) b 2013; WATERLOW (UK 1930) b 2013; AITKEN (UK 1916) b 2014 Baron Beaverbrook; MADDEN (UK 1919) b 2014; DUNNINGTON-JEFFERSON (UK 1958) b 2015
Of course there may be gains in the number of baronetcies but these can only come about by new creations (probably unlikely now) or by a successful claim to a dormant baronetcy. The following 14 dormant baronetcies have known male heirs who may be in a position to make a successful claim though unlikely in some cases:-
BURNETT of Leys (NS 1626) dormant in 1959 (presumed heir the Ramsay baronets of Balmain (UK 1806)
CAMPBELL of Glenorchy (NS 1625) (Earl of Breadlabane and Holland) dormant in 1995
GARDNER of Uttoxeter (GB 1794) (Baron Gardner) dormant in 1883
HAY of Smithfield (NS 1635) dormant in 1966 (presumed heir the Marquess of Tweedale)
LESLIE of Wardis and of Findrassie (NS 1625) dormant in 1967 (presumed heir the Leslie baronets of Glaslough (UK 1876)
PARKYNS of Bunney Park (E 1681) dormant in 1926
RICH of Shirley House (GB 1791) dormant in 1983
SMITH of Eardiston (UK 1809) dormant in 2000
SOMERVILLE of Dublin (I 1748) dormant in 1929
Von FRIESENDORFF of Hirdech (E 1661) dormant in 1670
STIRLING of Glorat (NS 1666) dormant in 1949
WARREN of Warrenscourt (I 1784) dormant in 2006
WOLSELEY of Mount Wolseley (I 1745) dormant in 1991
WYVILL of Constable Burton (E 1611) dormant in 1774
If we look at the number of baronets (as opposed to baronetcies ie eliminating peers and "double" baronetcies) then as well as the losses set out above there a number of losses and gains that may be likely on the above basis and bearing in mind there are about 976 current baronets:-
Losses:
GREY (UK 1814) – the current baronet (Sir Anthony Grey) b 1949 is an heir to the Earl Grey (also a baronet – GB 1746) - there is only one heir to the earldom under the age of 35 (a cousin b 1982) before it would devolve on Sir Anthony leading to the loss of a baronet. However Sir Anthony himself only has one heir under the age of 35 (his only son Thomas Grey b 1998) before the 1814 baronetcy would become extinct and the earldom and the 1746 baronetcy would devolve on other kinsmen of the current Earl
HOBART (UK 1914) – the current baronet (Sir John Hobart) b 1945 is the heir presumptive to the Earl of Buckinghamshire (also a baronet – E 1611) b 1944 who is married but without issue. This (second) baronetcy is therefore almost certain to be subsumed into the earldom
NAIRN (UK 1904) – there is only one life under 35 (grandson of current baronet b 2008) before the baronetcy would devolve on the Spencer-Nairn baronets (UK 1933)
PEASE (UK 1882) – the current baronet Sir Joseph Pease was b 1927 and his only son Charles Pease b 1955 but unmarried is the only heir before the baronetcy would devolve on Baron Gainsford (UK 1916) thus it is almost certain this baronetcy would be absorbed in that barony
POLLOCK (UK 1866) – the current baronet Sir George Pollock was b 1928 and his only son David Pollock b 1959 though married is without male issue and then there are no heirs under 35 before the baronetcy would devolve on Viscount Hanworth (UK 1936) so it is possible this baronetcy would be absorbed in that viscountcy
PONSONBY (UK 1956) – the current baronet (Sir Charles Ponsonby) b 1951 is second heir to Baron de Mauley b 1957 who is married but without issue. His heir presumptive is his younger brother Hon Ashley Ponsonby b 1959 who although married is also without issue. This baronetcy is therefore almost certain to be absorbed into the barony.
ROPNER (UK 1904) – there are no heirs under 35 before the baronetcy would devolve on the Ropner baronets (UK 1952). However there are no heirs to that baronetcy (the current baronet was b 1981 and is married though without issue) so the 1952 baronetcy may become extinct at which point the 1904 baronetcy would be inherited by kinsmen of the current 1904 baronet
SINCLAIR (NS 1604) - the current (11th) baronet (Sir William Sinclair) b 1979 is second heir to the Earl of Caithness (also a baronet – NS 1631) b 1948 whose heir (Lord Berriedale b 1981) is unmarried. It is possible that this baronetcy may be subsumed into the earldom. Sir William has no known heirs (other than the Earl of Caithness and Lord Berriedale) so the titles may become dormant. Alternatively if Sir William remains unmarried and predeceases the Earl of Caithness or Lord Berriedale it may be either of the latter who inherits the 1604 Sinclair baronetcy. Either way the number of baronets will be reduced by one.
Gains:
ASTLEY (E 1660) – this baronetcy is held by Baron Hastings (E 1290) b 1960 but he has only one heir under 35 (his only son Hon Jacob Astley b 1991) before the barony would go into abeyance or devolve on a female heir in which case the baronetcy would become separated from the barony although the only heirs to the baronetcy under 50 were born in 1975, 1976 and 1977 and none are married according to Debretts
BARING (GB 1793) – this baronetcy is held by Baron Northbrook (UK 1866) b 1954 and married but without male issue and there are no heirs to the barony so it seems almost certain that the barony will become extinct thus releasing the baronetcy to which there are heirs
EDEN (E 1672 and GB 1776) – the current baronet is a life peer (Baron Eden of Winton cr 1983) b 1925 and so on his death the baronetcies will be released. However there is only one heir under the age of 35 (a grandson b 1991) before the baronetcies would devolve on Baron Auckland so there may be only the temporary gain of a baronet.
HAZLERIGG (E 1622) – this baronetcy is held by Baron Hazlerigg (UK 1945) b 1951 who has only son Hon Arthur Hazlerigg b 1987 but unmarried. There are no other heirs to the barony under the age of 50 so the barony may become extinct thus releasing the baronetcy to which there are heirs.
HICKS BEACH (E 1619) – this baronetcy is held by the Earl of St Aldwyn (UK 1915) b 1950 and married but without male issue and there is only one heir (nephew b 1998) under age of 35 preventing extinction of the earldom and release of the baronetcy to which there are other heirs.
ROTHSCHILD (UK 1847) – this baronetcy is held by Baron Rothschild (UK 1885) b 1936 who has only son Hon Nathaniel Rothschild b 1971 divorced without issue. There is only one other heir under 35 (nephew b 1985) preventing extinction of the barony and release of the baronetcy to which there are other heirs.
VANDEN-BEMPDE-JOHNSTONE (GB 1795) – this baronetcy is held by Baron Derwent (UK 1881) b 1930 who has an only son Hon Francis Vanden-Bempde-Johnstone b 1965 who although married has no male issue. There are no other heirs to the barony so it seems almost certain that the barony will become extinct thus releasing the older baronetcy to which there are heirs.
YOUNG (UK 1813) – this baronetcy is held by a life peer (Baron Young of Cookham cr 2015) b 1941 and so on his death the baronetcy would be released.
Sinclear of Dunbeath (cr 1704)Was the current Baronet (b 1979, succ 2011) without an heir when he succeeded? There is still a chance of an heir - is he married?