Duchess of York is a title held by the wife of the Duke of York since the first Duke of York in 1384. The title is gained with matrimony alone and is forfeited on divorce. Because four of the twelve Dukes of York did not marry or had already assumed the throne when they married, there have only ever been eleven Duchesses of York. Wikipedia
The definitive Wikipedia entry for Duchess Of York. Wikipedia is the biggest multilingual free-content encyclopedia on the Internet. en.wikipedia.org/wiki/Duchess_of_York
