Nicholas Duke Biddle, a scion of two prominent American families who helped refugees from Cuba and other Caribbean countries, died in October 2004 in Madrid. He was 83. The cause was a heart attack, his cousin Tony Duke said. Mr. Biddle was originally named Anthony Joseph Drexel Biddle III, after his father, Anthony Joseph Drexel Biddle Jr., a prominent diplomat. His parents divorced in 1931, and in 1938, his mother, the former Mary Duke -- whose father was a founder of Duke University -- legally changed his given names. Later, the elder Mr. Biddle gave his name to a son from another marriage. Mr. Biddle graduated from St. Paul's School and Harvard and studied at Columbia Law School. He served in the 82nd Airborne Division in Europe during World War II, and afterward spent five years as a foreign service officer at the United States Embassy in Madrid. He later pursued investment banking and other business and philanthropic interests, living in Madrid, Manhattan and Palm Beach.Mr. Biddle served for many years on the board of the International Rescue Committee, concentrating on helping refugees from Caribbean countries. He went to Cuba soon after Castro took power to help people who wanted to leave. Mr. Biddle's first three marriages, to Paula Deckla, Anne M. Bullitt and Nancy Harris Preston, ended in divorce. He is survived by his wife of 28 years, the former Elena Thiebaut; a daughter, Pandora Biddle Hentic of Southampton, N.Y.; a son, George Craig Biddle of Manhattan; a stepdaughter, Lucille Preston Herbert of Manhattan; two sisters, Mary Duke Biddle Semans of Durham, N.C., and Margaret Biddle of California; a brother, Anthony Joseph Drexel Biddle III of Philadelphia; and four grandchildren.