Gilbert was born at Kelvedon Hatch, Essex, on 25 October 1883, the only son of a retired army officer, Arthur Stronge Gilbert (1839-1913), and Melvina Kundiher Singh (1860-1913), the daughter of Randhir Singh, the Raja of Kapurthala, and of Rajkumari Bibiji (née Henrietta Hodges and later Henrietta Melvina Oliver) (c. 1843-1893).
According to his wife, she and Gilbert were taking a walk in the Latin Quarter of Paris when they passed Shakespeare and Company, and saw some typescript pages of a French translation of Ulysses by Auguste Morel and Valery Larbaud displayed in the window.
The Harry Ransom Humanities Research Center at the University of Texas has archival material regarding his relationship with James Joyce and his work as a translator.
[13][14][15] One of Gilbert's major projects was the translation from French of Roger Martin du Gard's novel sequence Les Thibault.
In the last decade of his life Gilbert translated numerous texts for the Swiss art book publisher Albert Skira.