This branch of the family was descended from William, 1st Count Bentinck (1704-1774), the 1st Earl of Portland's second son (and the eldest by his second marriage to Jane Temple). Count William inherited his father's Dutch estates, and was educated and lived all his adult life in the Netherlands. In 1732 he was created Graf (Count) Bentinck. In 1733 he married Countess Charlotte Sophie von Aldenburg (1715-1800), daughter of Anton II, Count of Aldenburg and his wife Wilhelmine Maria, Princess of Hesse-Homburg. They had two sons: Christian Antoine (1734-1768) and John Albert (1737-1775). The brothers married sisters: Baroness Maria Catherine and Baroness Renira van Tuyll van Serooskerken. Whereas Christian inherited the Bentincks' Dutch estates, John Albert inherited the Earl of Portland's estate at Terrington St Clement, Norfolk, and settled in England. He became a British naval captain and fought in the Seven Years War. He invented and improved many mechanical devices used in ships, the best-known of which is the 'Coles-Bentinck' chain-pump, which was adopted for use in all Royal Navy ships.
The marriage of Count William and Countess Charlotte Sophie did not last and in the resulting separation settlement it was agreed that the Countess would keep her paternal family estates in Germany (Varel and Kniphausen, near Oldenburg), but that she would retain only a life interest in her Dutch estate at Doorwerth, on which there were heavy debts from her father's day. Bitter disputes arose between the Countess and Count William, and in 1754 an agreement was forced on the Countess, making her eldest son Christian the Lord of Varel and Kniphausen. His ownership was confirmed by Charlotte Sophie in 1757. She was not allowed to see her sons, and they both died before she could meet them again. The Countess - together with her two illegitimate sons - lived in various places including Leipzig and Vienna. She settled in Hamburg around 1767 and remained there for the rest of her life.
After Count William's death in 1774, the dispute escalated. Charlotte Sophie's daughter-in-law Catherine Maria Bentinck, née Tuyll van Serooskerken, took possession of Doorwerth on behalf of her young children, despite the fact that the Countess had been employing her own people there. A legal case over the ownership of the Doorwerth estate was heard at The Hague in 1781. The Countess won the case, and by 1782 her agents were administering the estate on her behalf. In the turmoil caused by the French invasion of the Netherlands in the 1790s, Countess Charlotte Sophie agreed to bequeath Doorwerth to her eldest grandson William G.F. Bentinck, Count Bentinck-Rhoon (1762-1835), who claimed it as the eldest son of Count Christian. However, this agreement was later rescinded by both parties, and when the Countess died in 1800 she bequeathed Doorworth instead to another of her grandsons, Vice-Admiral William Bentinck (1764-1813) of Terrington St Clement, the eldest son of Captain John Albert Bentinck. The Countess had met William for the first time in 1789, when he travelled to Germany to meet her with his friend James Hawkings-Whitshed. Whitshed later married William's sister Sophia H. Bentinck, with whom the Countess had an intimate correspondence until her death in 1800.
Vice-Admiral Bentinck bequeathed Doorwerth in his will to his third, posthumous son, Charles Aldenburg Bentinck (1810-1891). Legal business concerning Doorwerth was handled by his widow, Lady Frances Bentinck (c.1781-1847), until Charles came of age. Doorwerth was sold by Charles in 1837.
Varel and Kniphausen were inherited by Christian's son, William G.F. Bentinck, Count Bentinck-Rhoon. He died in 1835 without surviving male heirs. A dispute over the succession was only settled in 1854, when the Bentinck family were compensated for their property and sovereign rights, and Varel and Kniphausen became incorporated into the Grand Duchy of Oldenburg.
The Bentincks' Dutch possessions, including the seigneury of Pendrecht and Rhoon, passed in turn to Count Bentinck-Rhoon's nephews William F.C. Bentinck (1787-1855) and Charles A.F. Bentinck (1792-1862). This branch of the family became settled in England during the late 18th century. Timothy Bentinck, the current 8th Count Bentinck (and 12th Earl of Portland) descends from Charles A.F. Bentinck.