whom they found fat, jolly and affable, who talks of Ly Augusta as his wife and seems much attached to her

this fat jolly and affable Royal was the Duke of Sussex, more properly, Prince Augustus Frederick, Duke of Sussex (27 January 1773 – 21 April 1843), was the sixth son of George III and his consort, Queen Charlotte. He was the only surviving son of George III who did not pursue an army or naval career.

This is what the Oxford Dictionary of National Biography has to say about him: it makes for interesting reading.......

Augustus Frederick, Prince, duke of Sussex (1773–1843), sixth son and ninth child of George III and Queen Charlotte, was born at Buckingham House (later Palace) on 27 January 1773. From 1786, when he entered the University of Göttingen, until 1804, he mostly resided abroad. As a young man, he suffered severely from asthma; too delicate to join the army or navy, at one stage he considered entering the church. His lengthy sojourn on the continent fostered his intellectual tastes, radical sympathies, and social horizons.

While living in Rome in the winter of 1792, the prince met and proposed to Lady Augusta Murray (bap. 1761, d. 1830), second daughter of the fourth earl of Dunmore. At first she refused, fearing his family's disapproval; but on 4 April 1793 they underwent a secret marriage ceremony, performed by a clergyman of the Church of England named Gunn, without any witnesses present.

To guard against the possibility of objections to the marriage from the fact that it had taken place in Roman Catholic Church jurisdiction, the ceremony was repeated at St George's, Hanover Square, London, on 5 December following, under the disguised names of Augustus Frederick and Augusta Murray.

This contravened the provisions of the Royal Marriages Act of 1772, and their union was declared void by the king in August 1794. There were two children of the marriage, Augustus Frederick (1794–1848), and Augusta Emma (1801–1866), who married Sir Thomas Wilde, later Lord Truro and lord chancellor. The children took the surname of D'Este, after Italian ancestors common to their parents, for Lady Augusta Murray was also of royal descent.

For some years the prince ignored the decision of the court, but ultimately he acquiesced. In 1809 he applied for the custody of his children, because he had heard that their mother was bringing them up to believe that ‘they were princes and princesses’. In 1806 Lady Augusta received royal licence to assume the name of D'Ameland instead of Murray. The son, Sir Augustus Frederick D'Este, made various efforts to get his claims recognized, and in 1831 filed a bill in chancery, ‘to prove the marriage good and valid’.

In 1801 Prince Augustus was created Duke of Sussex, Earl of Inverness, and Baron Arklow.

His liberal political views estranged him from his father and the court, and excluded him from lucrative employments similar to those enjoyed by the other royal dukes. He supported the progressive political policies of his time, including the abolition of the slave trade, Catholic emancipation, the removal of the civil disabilities of Jews and dissenters, the abolition of the corn laws, and parliamentary reform.

Once, when speaking to the House of Lords at inordinate length on Catholic emancipation and its historical precedents in the middle ages, a tory peer whispered to his neighbour that ‘His Royal Highness is deep in the Councils of Trent’. His colleague replied wearily, ‘I could wish it was the river’ (Fulford, 260). Such endorsement of whig principles often brought him into conflict with the prince regent and most of their more conservatively minded brothers.

The duke's interest in the advancement of art and science was genuine and enlightened, and he readily lent his influence to promote charitable schemes. In his later years he was in great demand as chairman at anniversary dinners. He became grand master of the freemasons in 1811. He was elected president of the Society of Arts in 1816, and from 1830 to 1838 was president of the Royal Society. In the latter capacity he gave brilliant receptions in his apartments at Kensington Palace, but the resulting expense induced him to resign the presidentship, as he preferred spending the money on his library. This collection, over 50,000 volumes strong, included about 1000 editions of the Bible, and many ancient manuscripts.

With the accession in 1830 of William IV (with whom he was on better terms than with George IV) the duke was restored to favour at court, and appointed ranger of the royal parks. On 2 May 1831 he married (again outside the terms of the Royal Marriages Act) Lady Cecilia (1793–1873), daughter of the second earl of Arran, and widow of Sir George Buggin. In 1840 she was created Duchess of Inverness. There were no children of this marriage. The duke died on 21 April 1843, at Kensington Palace. The Times commented that ‘No death in the royal family short of the actual demise of a monarch could have occasioned a stronger feeling of deprivation’ (22 April 1843). In his will he asked that his remains should not be interred with the royal family at Windsor, from which his wife would be excluded; he was buried in the public cemetery at Kensal Green on 4 May 1843.