Biography of William Bentinck, 1st Count Bentinck (1704-1774)
- [Hans] William Bentinck, 1st Earl of Portland (1649-1709)
- [William] Henry Bentinck, 1st Duke of Portland (1682-1726)
- William Bentinck, 1st Count Bentinck (1704-1774)
- Charlotte Sophie, Countess Bentinck, née Countess of Aldenburg (1715-1800)
- William Bentinck, 2nd Duke of Portland (1709-1762)
- Margaret Cavendish-Bentinck, Duchess of Portland (1715-1785)
- John Albert Bentinck (1737-1775; naval captain and M.P.)
- William Henry Cavendish Cavendish-Bentinck, 3rd Duke of Portland (1738-1809)
- William Bentinck (1764-1813; Vice-Admiral)
- William Henry Cavendish-Scott-Bentinck, 4th Duke of Portland (1768-1854)
- Lord William Henry Cavendish-Bentinck (1774-1839; M.P. and Governor General of India)
- William John Cavendish-Bentinck-Scott, 5th Duke of Portland (1800-1879)
- Lord [William] George Frederic Cavendish-Scott-Bentinck (1802-1848)
- Lord [William] Henry Cavendish-Bentinck (1804-1870)
- William John Arthur Charles James Cavendish-Bentinck, 6th Duke of Portland (1857-1943)
- Winifred Anna Cavendish-Bentinck, Duchess of Portland (1863-1954)
- William Arthur Henry Cavendish-Bentinck, 7th Duke of Portland (1893-1977)
- Ferdinand William Cavendish-Bentinck, 8th Duke of Portland (1888-1980)
- Victor Frederick William Cavendish-Bentinck, 9th Duke of Portland (1897-1990)
- Henry Noel Bentinck, 11th Earl of Portland (1919-1997)
- Timothy Charles Robert Noel Bentinck, 12th Earl of Portland (b 1953)
William Bentinck (known as Willem Bentinck in Dutch) was the first son of the second marriage of the 1st Earl of Portland. His half-brother Henry Bentinck, 1st Duke of Portland, inherited his father's English possessions. William inherited the Dutch lordships of Rhoon and Pendrecht.
Brought up initially in England, in his teens Bentinck and his younger brother Charles were sent to the Netherlands to be educated. Bentinck studied at the University of Leiden and at The Hague, and went on the Grand Tour in the late 1720s.
In 1732, his father paid for Bentinck's elevation to the rank of Imperial Count of the Holy Roman Empire. His increased rank enabled Bentinck's arranged marriage to Charlotte Sophie, the daughter of Anton II, Count of Aldenburg, the following year. The couple had two children, but the marriage was unhappy and they separated in 1738. The possessions which Charlotte Sophie had brought into the marriage were granted to William, but the division was contentious, and there were a number of lawsuits between them. The estate at Doorwerth in the Netherlands remained in Charlotte Sophie's possession, but was claimed by the widow of her eldest son after Count William's death in 1774, leading to more litigation.
Bentinck was an Orangist and a prominent politician in the States of Holland. He was agent for William IV, Prince of Orange, in the 1748 coup which placed Amsterdam in Orangist hands. He was also a diplomat, acting as one of the leading delegates of the Dutch Republic at the Congress of Aix-la-Chapelle in 1748. His influence waned after the death of William IV.
Bentinck married Charlotte Sophie, the only daughter of Anton II, Count of Aldenburg, in 1733. They had two sons before separating in 1738:
- Christian F. Anthony Bentinck (1734-1768), 2nd Count Bentinck, m Baroness Maria Catherine van Tuyll van Serooskerken (1743-1793), and had:
- William G.F. Bentinck (1762-1835), 3rd Count Bentinck, and Lord of Rhoon and Pendrecht, m Ottoline, Baroness of Reede-Lynden (1773-1799)
- John C. Bentinck (1763-1833), Major-General in the British Army, m Lady Jemima Reede, daughter of the 5th Earl of Athlone. From him descends Timothy Bentinck, the current Count Bentinck and 12th Earl of Portland
- Charles F. Bentinck (1764-1811), Dutch statesman
- Henry W. Bentinck (1765-1821), colonial governor of St Vincent and Demarara and Berbice
- Maria C.F. Bentinck (1767-1826)
- John Albert Bentinck (1737-1775), naval captain
- The Portland (Welbeck) Collection held in Manuscripts and Special Collections at The University of Nottingham contains letters from the 1st Count to the 3rd Duke of Portland (Pw F 1213-1264)
- Search for William Bentinck, 1704-1774, in the Manuscripts Online Catalogue, to retrieve other papers relating to him in the Portland (Welbeck), Portland (London) and Newcastle collections.
- The British Library, Manuscripts Department, holds personal and family papers (Eg MSS 1704-56, 1861-62), and correspondence (Add MSS 35410-35590 passim; Eg MSS 3421, 3481; and Add MSS 32701-32977 passim)
- The National Maritime Museum: The Caird Library, Manuscripts Section, holds correspondence with Lord Sandwich (MS 91/018)
- Schazmann, Paul-Emile, The Bentincks: The History of a European Family (London,1976) [King’s Meadow Campus East Midlands Collection Not 468.V38 BEN]
- van Huffel, Wilhelmina C., Willem Bentinck van Rhoon, zijn persoonlijkheid en leven (1725-1747) (Den Haag, 1923)
- Count Bentinck is mentioned within Charlotte Sophie, Countess Bentinck : her life and times 1715-1800, by her descendant Mrs Aubrey Le Blond (2 vols, London: Hutchinson, 1912)