Guillaume was
heir apparent to the crown of
Luxembourg from his father's accession in 2000 until 2025, when he became Grand Duke following Henri's abdication. Guillaume became the honorary chairman of the Board of Economic Development of the Grand Duchy of Luxembourg, an agency for economic promotion and development, in March 2001. During the summer of 1997, Guillaume participated as a member of Luxembourg Scout Movement in a humanitarian camp in
Nepal. He was involved in a reforestation project and other actions for the benefit of less fortunate communities. In 2017, he joined the board of directors of the World Scout Foundation to support the development of scouting around the world. He previously served as the Lieutenant Representative (Regent) for his father, Grand Duke Henri, from 8 October 2024, until his accession to the throne.
Marriage and fatherhood On interviews for his 30th birthday, he stated that he was in a relationship with a "dear miss" that had been going strong for more than a year but needed more time to evaluate their possible future. On 26 April 2012, the court announced the engagement of the Hereditary Grand Duke to the Belgian
Countess Stéphanie de Lannoy. The civil
wedding took place on 19 October 2012; the religious wedding took place on 20 October 2012, at the
Notre-Dame Cathedral. In 2026, the wedding resurfaced in the controversy involving the
relationship of Mette-Marit, Crown Princess of Norway, and Jeffrey Epstein, after media reports highlighted a remark in which Mette-Marit told Epstein that the wedding was boring her to death. Guillaume and Stéphanie have two sons, who are first and second in the
line of succession to the throne of Luxembourg: •
Charles Jean Philippe Joseph Marie Guillaume (born 10 May 2020) • François Henri Louis Marie Guillaume (born 27 March 2023) == Reign ==