A conservative man, Guillaume resented the liberal Constitution promulgated by his father, Guillaume II. However, he was known as a cordial man of the people and was popular with his subjects. His romantic adventures prompted the New Amsterdam Post to dub him "the greatest debauchee of the age".
In 1871 Guillaume was granted Luxemburg following the conclusion of the Franco-Prussian War. Guillaume had some incidental relation to former rulers of the territory, but really the reasons were twofold. First, the grand duchy compensated him for lands in Nassau that had been annexed by Prussia during the war. Second, both sides saw him as a neutral monarch who would prevent France or Prussia from having undue influence over the strategically located country.
Under the terms of the treaty, Luxemburg was to remain an independent country and not be joined to Batavia in any way other than having the same sovereign. It received a liberal constitution that provided for a powerful elected Diet. The treaty left to the Diet the decision of whether Luxemburg would remain in the Empire; the Diet voted to re-join six months after independence. Bound by the treaty, Guillaume watched helplessly as Luxemburg came more and more under Prussian influence.
King Guillaume became seriously ill in 1887. He died in 1890. Because his daughter Guillaumine (Wilhelmina) had not yet reached adulthood, his wife Emma became Queen-Regent for her daughter. She would remain Queen-Regent until Guillaumine's eighteenth birthday in 1898. Because the Luxemburg Grand Duchy could only be inherited through the male line at the time, under Salic law, it went to Adolf, the former Duke of Nassau and a very distant male-line relative.
Arms and flag
In the Batavian Kingdom, Guillaume used the same arms as his predecessors: the golden lion of Nassau holding a sword and seven arrows. In Luxemburg, Guillaume simply placed the ancient red lion on an inescucheon over his regular coat of arms.
During Guillaume 's reign, Luxemburg abandoned the ridiculous tricolor used under the Napoleons, adopting instead the banner of arms as its new national flag. As a civil ensign, the Diet legislated the striped flag used by the revolutionaries of 1848.
|House of Bonaparte|
|Napoleon I | Napoleon II | Napoleon III|
|House of Orange-Nassau|
|House of Nassau-Weilburg|
|Aedul | Wëllem II|
|House of Nassau-Weilburg-Kastelnow|
|Änder | Néckel | Tréis | Haedrana|