Successive Dutch kings and queens:
Luxembourg seceded when Wilhelmina came to the throne in 1890 at age 10 -- her mother, Queen Emma, acted as regent until Wilhelmina became 18 -- because at the time they were not willing to accept a queen. Instead a family member, Adolf, former Duke of Nassau, became the first Grand Duke of Luxembourg.
Also Napoleon set up [Louis Napoleon]? as king over the Netherlands, called the Kingdom of Holland, from 1806-1810.
The Dutch royal family today is much larger than it has ever been. Queen Beatrix and her husband, [Prince Claus]?, have three sons, Willem-Alexander?, [Johan Friso]? and Constantijn? (married to princess Laurentien?). Her sister Margriet and her spouse prince Pieter van Vollenhoven have four sons: Maurits, Bernhard, Pieter-Christiaan and Floris. These seven princes as well as Margriet, are all (potentially) legal heirs to the throne, although the first right goes to the Crown Prince, and after him to his brothers. The two other sisters of Beatrix, Irene and Christina, have renounced their rights to the throne due to marriages which were not officially approved by the Dutch government.
The crown prince is Willem-Alexander (born 1967), prince of Oranje-Nassau. His fiancée is [Maxima Zorreguieta Cerruti]?, whose father was a minister of agriculture in the dictatorial regime under general Vidéla in Argentina.
Abdication of the throne has occurred several times. Queen Wilhemina and Queen Juliana both abdicated in favor of their daughters and Willem I abdicated in favor of his son.