Christian Louis de Massy
Christian Louis de Massy co-wrote with Charles Higham, his autobiography. As the nephew of Prince Rainier and Grace Kelly, his book was popular mostly with those still captivated by the story of a movie star marrying a real prince. However Christian makes it clear in his book, in repeated detail, how truly dysfunctional the entire Monegasque family (or the Grimaldis) truly are.
Christian's descend from royalty is rather surprising as his shortest path is not into any of the neighboring dynasties, but rather through Scotland, through the Badens, through Hesse-Darmstadt, and eventually up to Denmark.