Adolphe was Grand Duke of Luxembourg from 23 November 1890 to his death on 17 November 1905. The first grand duke from the House of Nassau-Weilburg, he succeeded King William III of the Netherlands, ending the personal union between the Netherlands and Luxembourg. Adolphe was Duke of Nassau from 20 August 1839 to 20 September 1866, when the Duchy was annexed to the Kingdom of Prussia.

The Grand Duke of Luxembourg is the head of state of Luxembourg. Luxembourg has been a grand duchy since 15 March 1815, when it was created from territory of the former Duchy of Luxembourg. It was in personal union with the United Kingdom of the Netherlands until 1890 under the House of Orange-Nassau. Luxembourg is the world's only sovereign Grand Duchy and since 1815, there have been nine monarchs, including the incumbent, Henri.