Morris Robinson (1715-1777) was the third surviving son of Matthew Robinson and Elizabeth Drake. On 5th January 1732 he was apprenticed to Thomas Marriott and became an attorney, working in the Six Clerks Office of the Court of Chancery in Lincoln’s Inn Fields. On 13th February 1757 he married Jane Greenland (1727-1810) in St Michael’s Church in Bath; their witnesses were his brother Charles Robinson and his sister Sarah Scott. They had two sons, Morris (1757-1829) and Matthew (1762-1831). Morris was to succeed his uncle Matthew Robinson Morris (1713-1800) as 3rd Baron Rokeby and Matthew was adopted by his aunt, Elizabeth Montagu, and took the surname Montagu.

At the age of 18 Morris fathered an illegitimate child, Mary Arnold (b.1733) with Rosamond Arnold. Mary Arnold would go on to become the companion and literary executor of Morris' sister, Sarah Scott and lived with her at Batheaston and during her final years at Catton in Norfolk. Morris did not officially recognise her as his daughter, but he did leave a quarter of his estate to her in his will, the same proportion that he left to his elder son Morris. (Unfortunately there was little left once his debts were paid.)

Morris’s sisters, Elizabeth Montagu and Sarah Scott, disapproved of his choice of wife, regarding her as spendthrift. They may also have been unhappy at the haste of their marriage: their first son was born only five months later. When Morris died unexpectedly on a visit to Ireland, it was discovered that their London house was mortgaged and he had little in the way of free assets. His father, Matthew Robinson, and sister Elizabeth Montagu together provided an annuity of £150 to support his widow.

Morris died in Dublin and was buried in a vault in Armagh Cathedral that had been acquired by his father’s second cousin, Rt. Revd. Richard Robinson, Archbishop of Armagh.