Question: what is the date of creation of the Marquess of Wharton title that could be listed as a new Barony ?

text: List of marquessates in the peerages of Britain and Ireland
Marquessates in the Peerage of Great Britain , 1707–1801

This page lists all marquessates, extant, extinct, dormant, abeyant, or forfeit, in the peerages of England, Scotland, Great Britain, Ireland, and the United Kingdom. The title of Marquess of Dublin, which is perhaps best described as Anglo-Irish, was the first to be created, in 1385, but like the next few creations, the title was soon forfeit. The title of Marquess of Pembroke, created in 1532 by Henry VIII for Anne Boleyn, has the distinction of being the first English hereditary peerage granted to a woman in her own right (styled Marchioness in the patent). The English title Marquess of Winchester, created in 1551, is the earliest still extant, so is Premier Marquess of England. The title long remained less common, and on the evening of the Coronation of Queen Victoria in 1838, the Prime Minister Lord Melbourne explained to her (from her journals):
Title Date of creation Surname Current status Notes
Marquess of Beverley 26 May 1708 Douglas Extinct 22 October 1778 Subsidiary title of the Duke of Dover , who was also Duke of Queensberry and Marquess of Dumfriesshire in the Peerage of Scotland ; also Marquess of Queensberry 1708-1711 and 1715-1778
Marquess of Wharton 15 February 1715 Wharton Extinct 31 May 1731 Also Marquess of Malmesbury and Marquess of Catherlough in Ireland ; created Duke of Wharton in 1718
Marquess of Malmesbury 15 February 1715 Wharton Extinct 31 May 1731 Also Marquess of Wharton and Marquess of Catherlough in Ireland ; created Duke of Wharton in 1718
Marquess of Clare 11 August 1715 Pelham-Holles Extinct 1768 Subsidiary title of the Duke of Newcastle-upon-Tyne
Marquess of Titchfield 6 July 1716 Bentinck Extinct 30 July 1990 Subsidiary title of the Duke of Portland
Marquess of Carnarvon 29 April 1719 Brydges Extinct 29 September 1789 Subsidiary title of the Duke of Chandos
Marquess of Brackley 18 June 1720 Egerton Extinct 8 March 1803 Subsidiary title of the Duke of Bridgewater
Marquess of the Isle of Ely 26 July 1726 Guelph Merged in crown 25 October 1760 Subsidiary title of the Duke of Edinburgh ; also Prince of Wales from 1727 ; also Duke of Cornwall in England and Duke of Rothesay in Scotland 1727-1751 . The marquessate was apparently erroneously gazetted as Marquess of the Isle of Wight although Marquess of the Isle of Ely was the intended title . In later editions of the London Gazette the Duke is referred to as the Marquess of the Isle of Ely
Marquess of Berkhampstead 27 July 1726 Guelph Extinct 31 October 1765 Subsidiary title of the Duke of Cumberland
Marquess Grey 19 May 1740 Grey Extinct 19 January 1797 Also Duke of Kent until 1740 , when this title became extinct ; passed by special patent to his granddaughter
Marquess of Rockingham 19 April 1746 Watson-Wentworth Extinct 2 July 1782
Marquess of Monthermer 5 November 1766 Montagu Extinct 23 May 1790 Subsidiary title of the Duke of Montagu
Marquess of Buckingham 4 December 1784 Temple-Nugent-Grenville Extinct 26 March 1889 Created Duke of Buckingham and Chandos in 1822
Marquess of Lansdowne 6 December 1784 Petty-Fitzmaurice Extant
Marquess of Stafford 1 March 1786 Leveson-Gower Extant Created Duke of Sutherland in 1833
Marquess Townshend 31 October 1787 Townshend Extant
Marquess of Salisbury 18 August 1789 Cecil Extant
Marquess of Bath 24 August 1789 Thynne Extant
Marquess of Abercorn 15 October 1790 Hamilton Extant Created Duke of Abercorn in Ireland in 1868
Marquess Cornwallis 8 October 1792 Cornwallis Extinct 9 August 1823