"Nica" de Koenigswarter, née Rothschild, was one of four children of Charles Rothschild, of the wealthy Anglo-Jewish banking family, and his wife Rozsika Edle von Wertheimstein, a Hungarian baroness. Her father was a pioneering naturalist and entomologist, and the source of her unusual given name was either a species of butterfly or a rare moth. She came out as a debutante and studied art bistory in Venice, Vienna, and Munich. In 1935, she married Baron Jules de Koenigswarter, a French diplomat, with whom she had five children. During World War II, she worked for the government-in-exile of Charles de Gaulle. After the war, she separated from her husband and moved to New York City to become a friend, patron and muse of jazz musicians, especially Thelonious Monk and Charlie Parker. She hosted jam sessions in her home and earned the nicknames "bebop baroness" and "jazz baroness." In the mid-1970s, after Monk ended his public performances, he retired to her home in New Jersey. Many musicians wrote and dedicated pieces in her honor, including Gigi Gryce's "Nica's Tempo", Sonny Clark's "Nica", Horace Silver's "Nica's Dream", Kenny Dorham's "Tonica", Kenny Drew's "Blues for Nica", Freddie Redd's "Nica Steps Out", Tommy Flanagan's "Thelonica" and Thelonious Monk's "Pannonica." Her book Les musiciens de jazz et leurs trois vœux (English title, Three Wishes: An Intimate Look at Jazz Greats), a compilation of interviews with 300 musicians, accompanied by her photographs, was first published in France in the 1960s and reissued in 2006.