He was the author of several books, including critically acclaimed biographies of Alberto Giacometti and Pablo Picasso.
[1][2] He appeared in the documentary films Balthus Through the Looking Glass (1996) and Picasso: Magic, Sex, Death (2001).
[1] His father was a stockbroker, and until the Wall Street crash the family lived, as Lord put it, in "the lower echelons of the upper classes".
He served in the United States Army during World War II and was part of the Ritchie Boys who specialized in Military Intelligence.
He wrote about his experiences in his book, My Queer War which discusses keeping his homosexuality carefully hidden.