Jacques-Emile Blanche could be described as a Franco-British Max Beerbohm – an asexual snob, dandy and brilliant observer of his fellow men. He was brought up in a genteel lunatic asylum. Blanche’s father and grandfather were both psychiatrists and the Hôtel de Lamballe where Blanche was born in 1861, in the well-to-do Paris suburb of Auteuil, was both home and clinic. Theo Van Gogh and Guy de Maupassant were both treated there, and the less deranged inmates mingled freely with the family. It was a strange environment in which to grow up for a sensitive boy, whose only childhood confidant, his elder brother Joseph, died aged 12. Jane Roberts, who has written the first biography of Blanche to appear in English, has an eye for character and gets as much pleasure in describing the quirks of Dr Blanche’s patients as, later, she derives from the excesses of the glitterati of belle époque Paris.

Blanche’s childhood experiences, including his precocious and careful study of the British inmates, especially the Reverend Henry Marsh, a long-term resident, seem to have stood him in good stead when in the summer of 1870, at the height of the Franco-Prussian war, his overprotective mother packed him off to London.