SOCIETY FOR CONSTITUTIONAL INFORMATION: Richard Slater Milnes of Newland Park nr Wakefield proposed member 18.4.1783 by John Cartwright (by letter) 2nded Jeremiah Batley. / James Milnes of Wakefield proposed member 30.1.1784 by George Lloyd (by letter?) 2nded Edward Bridgen / John Milnes of Wakefield proposed member 13.2.1784 by William Smith 2nded Thomas Brand Hollis
For the common ancestry of these cousins see Betham's Baronetage 1805 vol 5 no 468.
Richard Milnes d 1706 married Elizabeth Wilson. Their son John d 1742 married Elizabeth Lapidge and their son James 1721-1792 married Ester Widowes and their son James 1755-1805 historyofparliamentonline (1790-1820) was the SCI member. He and his father were both listed in the Unitarian Society 1791.
An older son of Richard & Elizabeth Milnes was Robert d 1737 who married Hannah Poole and had a son Richard d 1755 who married Bridget Pemberton, their son Robert d 1778 by his first wife Joyce Slater was father of Richard Slater Milnes 1759-1804 historyofparliamentonline (1754-1790 & 1790-1820) the SCI member.
A younger son of Robert & Hannah Milnes was John d 1771 who married Mary Shore and was father of John Milnes 1751-1810 the SCI member. Public Advertiser 30.10.1778 "York, Oct. 27. A few Days ago was married at Harrogate, John Milnes, of Wakefield, Esq; to Lady Rachael Bruce, Daughter to the late Lord Elgin". John Milnes subscr 1782 to Sermons of Rev Robt Hood & to Moxon's Collation, 1790 to Geo Walker's Sermons, 1792 to Malton's Tour, &1800 to Steele's Essay on Gardening. Betham's Baronetage 1805 didn't mention a marriage to Lady Rachael Bruce but said "John Milnes, late of Wakefield, and of Page Hall, Esq. in the parish of Sheffield, now of Lower Canada, a deputy-lieutenant and in the commission of the peace for the West Riding of the county of York, born at Wakefield, 15th December, 1751, who married Catherine, daughter of Edward Carr, of Cledmond, in the county of Carlow, Ireland, and had had issue, Alfred-Shore Milnes, born at Paris, 21st May, 1792, and baptized at the Old Jewry, London; William-Poole Milnes, born at Brompton, in Middlesex, 25th March, 1796, and baptized at Wakefield; John Milnes, born at Wakefield, 13th August, 1799, all living; Caroline, born in London, 14th November, 1797, and baptized with her brother John, at Wakefield, died there, 12th April 1800, and was buried in the family vault". The Wakefield baptisms were at West Gate Presbyterian, John & Caroline on 11.4.1800 (the day before Caroline died), and William Poole on 14.4.1805. John Milnes' older brother Robert Shore Milnes (1747-1837) was Lieutenant Governor of Lower Canada from 1799 to 1805. The will PCC of Catherine Milnes wife of John Milnes of Wakefield proved 7.2.1807 by her husband John was dated 12.9.1792 and left all to her son Alfred Shore Milnes. I have found no record of the death of Rachel Milnes but there was a marriage at St Paul's, Canterbury on 9.9.1802 of a John Milnes and Catherine Carr. Hull Packet 13.3.1810 deaths "Last week, at Meersbrook, near Sheffield, aged 54, John Milnes, Esq. of Wakefield". Nat Arch IR 26/435/131 John Milnes of Wakefield Esq will proved at York 30.8.1811. Alfred Shore Milnes, Lt RA died in 1865 and his brother John proved his will value under £100