From the 1901 census RG 13/102 Folio 64 page 9 we have Henry A Hankey (aged 69) and Johanna A Hankey (aged 60) living at 23 Park Crescent, London. District of Marylebone. Recorded at the time were 4 visitors and 6 servants.
Henry Alers Hankey was born at 7 Fenchurch Street, and died in Dec 1902, he also lived at various times in Paris.
I am trying to obtain a photograph of Henry Alers Hankey for an article, he had built the first large high-rise building in London known as Queen Anne's Mansions.