Question: Who was the legal grandson of the Earl of Merica?

Context paragraphs:
Baron Skelmersdale: Baron Skelmersdale, of Skelmersdale in the County Palatine of Lancaster, is a title in the Peerage of the United Kingdom.  It was created in 1828 for the former Member of Parliament for Westbury, Newcastle-under-Lyme, Clitheroe and Dover, Edward Bootle-Wilbraham.  His grandson, the second Baron (the son of the Hon. Richard Bootle-Wilbraham), was a Conservative politician and served in the Conservative administrations of Disraeli and Lord Salisbury.  In 1880 he was created Earl of Lathom, in the County Palatine of Lancaster, in the Peerage of the United Kingdom.  However, the earldom became extinct on the death of his grandson, the third Earl, in 1930.  The barony passed to the last Earl's second cousin, the fifth Baron, who was the grandson of a younger son of the first Baron.  On his death the title was inherited by his cousin, the sixth Baron.

Ælfgar, Earl of Mercia: Ælfgar (died c. 1060) was the son of Leofric, Earl of Mercia, by his famous mother Godgifu (Lady Godiva).  He succeeded to his father's title and responsibilities on the latter's death in 1057.  He gained the additional title of Earl of East Anglia, but also was exiled for a time.  Through the first marriage of his daughter he would become father-in-law of the Welsh king Gruffydd ap Llywelyn; a few years after his death, his daughter would become a widow and marry English King Harold.

Viscount Fauconberg: Viscount Fauconberg, of Henknowle in the Bishopric of Durham, was a title in the Peerage of England held by the head of the Belasyse family.  This family descended from Sir Henry Belasyse, High Sheriff of Yorkshire from 1603 to 1604, who was created a Baronet, of Newborough in the County of York, in the Baronetage of England in 1611.  His son, Sir Thomas, the second Baronet, was created Baron Fauconberg, of Yarm in the County of York, in the Peerage of England in 1627.  In 1643 he was further honoured when he was made Viscount Fauconberg, of Henknowle in the Bishopric of Durham, also in the Peerage of England.  He was succeeded by his grandson, Thomas, the second Viscount, the son of the Honourable Henry Belasyse.  Thomas was created Earl Fauconberg in the Peerage of England in 1689.  He was childless and the earldom became extinct on his death in 1700.  He was succeeded in the remaining titles by his nephew and namesake, Thomas, the third Viscount, the son of Sir Rowland Belasyse.  The third Viscount was succeeded by his son, Thomas, the fourth Viscount, who in 1756 was created Earl Fauconberg, of Newborough in the County of York, in the Peerage of Great Britain.  The Earl's son Thomas, the second Earl, had no sons and the earldom became extinct on his death in 1802.  He was succeeded in the remaining titles by his second cousin Rowland Belasyse, the sixth Viscount, the grandson and namesake of Rowland Belasyse, younger brother of the third Viscount.  The sixth Viscount was succeeded by his younger brother, Charles the seventh Viscount, on whose death in 1815 all the titles became extinct.

Earl of Selborne: Earl of Selborne, in the County of Southampton, is a title in the Peerage of the United Kingdom.  It was created in 1882 for the lawyer and Liberal politician Roundell Palmer, 1st Baron Selborne, along with the subsidiary title of Viscount Wolmer, of Blackmoor in the County of Southampton.  He had already been made Baron Selborne, of Selborne in the County of Southampton, in 1872, also in the Peerage of the United Kingdom.  Both his son, the second Earl, and grandson, the third Earl, were prominent Liberal Unionist politicians.  The latter was in 1941 called to the House of Lords through a writ of acceleration in his father's barony of Selborne.  As of 2009 the titles are held by the third Earl's grandson, the fourth Earl.  He is one of the ninety elected hereditary peers that remain in the House of Lords after the passing of the House of Lords Act 1999, and sits as a Conservative.

Hugh Courtenay (died 1425): Sir Hugh I Courtenay (after 1358 – 5 or 6 March 1425), of Boconnoc in Cornwall and of Haccombe in Devon, was Sheriff of Devon for 1418/19 and was thrice elected knight of the shire for Devon in 1395, 1397 and 1421.  He was a grandson of Hugh de Courtenay, 2nd/10th Earl of Devon (1303–1377), was the younger brother of Edward de Courtenay, 3rd/11th Earl of Devon (1357–1419), "The Blind Earl", and was the grandfather of Edward Courtenay, 1st Earl of Devon (d.1509), KG, created Earl of Devon in 1485 by King Henry VII.  He was the link between the senior line of the Courtenay Earls of Devon made extinct following the Battle of Tewkesbury in 1471 (his elder brother's line) and the post-Wars of the Roses creation of a new Earldom for his grandson made in 1485 by King Henry VII.

Ealdgyth, daughter of Earl Ælfgar: Ealdgyth ("fl.  c".  1057–1066), also Aldgyth or in modern English, Edith, was a daughter of Ælfgar, Earl of Mercia, the wife of Gruffudd ap Llywelyn (d. 1063), ruler of all Wales, and later the wife and queen consort of Harold Godwineson, king of England in 1066.  She was described by William of Jumièges as a considerable beauty.

Earl of Berkshire: Earl of Berkshire is a title that has been created twice in the Peerage of England.  It was created for the first time in 1621 for Francis Norris, 1st Earl of Berkshire.  For more information on this creation (which became extinct on his death in 1622), see the Earl of Abingdon and also the Earl of Lindsey.  The second creation came in 1626 in favour of Thomas Howard, 1st Viscount Andover.  He was the second son of Thomas Howard, 1st Earl of Suffolk, second son of the second marriage of Thomas Howard, 4th Duke of Norfolk.  His mother was Katherine, daughter of Sir Henry Knyvett of Charlton in Wiltshire.  Howard had already been created Baron Howard of Charlton, in the County of Wiltshire, and Viscount Andover, in the County of Southampton, in 1622.  These titles are also in the Peerage of England.  Lord Berkshire succeeded to the Charlton estate through his mother in 1638.  He was succeeded by his eldest son, the second Earl.  He had already in 1640 been summoned to the House of Lords through a writ of acceleration in his father's junior title of Baron Howard of Charlton.  He had no sons and on his death in 1679 the titles passed to his younger brother, the third Earl.  He represented Wallingford in the House of Commons.  He also died without male issue and was succeeded by his great-nephew, the fourth Earl.  He was the grandson of the Hon. William Howard, fourth son of the first Earl.  In 1745 he succeeded his third cousin as eleventh Earl of Suffolk.  For further history of the titles, see the Earl of Suffolk.

Earl of Lanesborough: Earl of Lanesborough was a title in the Peerage of Ireland.  It was created in 1756 for Humphrey Butler, 2nd Viscount Lanesborough.  The Butler family descended from Theophilus Butler, who represented County Cavan and Belturbet in the Irish House of Commons.  In 1715 he was raised to the Peerage of Ireland as Baron Newtown-Butler, of the County of Fermanagh, with remainder to the heirs male of his father.  He was succeeded according to the special remainder by his brother, Brinsley, the second Baron.  He had previously represented Kells and Belturbet in the Irish Parliament.  In 1728 he was created Viscount Lanesborough in the Peerage of Ireland.  He was succeeded by his son, Humphrey, the aforementioned second Viscount, who was elevated to an earldom in 1728.  The first Earl was succeeded by his son, Brinsley, the second Earl.  He represented County Cavan in the Irish House of Commons.  His grandson, the fifth Earl, sat in the British House of Lords as an Irish Representative Peer from 1849 to 1866.  The latter was succeeded by his nephew, the sixth Earl.  He served as Lord-Lieutenant of Cavan from 1876 to 1900 and was an Irish Representative Peer from 1870 to 1905.  He was succeeded by his son, the seventh Earl.  He was an Irish Representative Peer from 1913 to 1929.  On his death the titles passed to his younger brother, the eighth Earl.  The titles became extinct on the death of the latter's eldest son, the ninth Earl, in 1998.

Earl of Clonmell: Earl of Clonmell, in the County of Tipperary, was a title in the Peerage of Ireland.  It was created in 1793 for John Scott, 1st Viscount Clonmell, Lord Chief Justice of the King's Bench for Ireland.  He had already been created Baron Earlsfort, of Lisson-Earl in the County of Tipperary, in 1784, and Viscount Clonmell in 1789.  These titles were also in the Peerage of Ireland.  He was succeeded by his son, the second Earl.  He sat as Member of Parliament for New Romney.  His grandson, the fourth Earl, was elected an Irish Representative Peer in 1874.  The latter never married and was succeeded by his younger brother, the fifth Earl.  He was a Lieutenant-Colonel in the Rifle Brigade and fought in the Ashanti War.  He was childless and was succeeded by his first cousin, the sixth Earl.  He was the eldest son of Colonel the Hon. Charles Grantham Scott, second son of the second Earl.  On his death the titles passed to his son, the seventh Earl.  He died without male issue and was succeeded by his seventy-five-year-old uncle, the eighth Earl.  The latter was childless and on his death in 1935 the titles became extinct.  Family homes included Bishopscourt (aka Bishop's Court) in County Kildare, Ireland (1838-1914) and Eathorpe Hall in Warwickshire, England (pre-1877 to post-1909).

Baron FitzWalter: Baron FitzWalter is an ancient title in the Peerage of England.  It was created in 1295 for Robert FitzWalter.  The title was created by writ, which means that it can descend through both male and female lines.  His great-grandson, the fourth Baron, was an Admiral of the Fleet.  The fourth baron's grandson, the seventh Baron, was succeeded by his daughter and only child, Elizabeth.  She was the wife of John Radcliffe.  Their son, the ninth Baron, was attainted for treason in 1495 with his title forfeited.  However, his son Robert Radcliffe obtained a reversal of the attainder by Act of Parliament in 1509 and later served as Lord Lieutenant of Lancashire.  He was created Viscount FitzWalter in 1525 and Earl of Sussex in 1529.  His grandson, the third Earl, was summoned to the House of Lords through a writ of acceleration in 1553 in his father's junior title of Baron FitzWalter.  Lord Sussex later served as Lord Deputy of Ireland.  He was succeeded by his younger brother, the fourth Earl.  He had earlier represented Maldon, Hampshire and Portsmouth in the House of Commons and also served as Lord Lieutenant of Hampshire.  When he died the titles passed to his only child, the fifth Earl.  He was Lord Lieutenant of Essex.

Supporting paragraphs: Ealdgyth, daughter of Earl Ælfgar Ælfgar, Earl of Mercia
Answer: Gruffudd ap Llywelyn