As World War I drew to a close, Prince Louis, at the age of forty-eight, remained without legitimate issue, unmarried, and unbetrothed.
So there was no cultural or dynastic aspect in the von Urachs’ past that was anti-French, rather the opposite; but this meant nothing in the climate of Revanche between the French Third Republic and the new Imperial Germany.
The 2nd Duke, a descendant through a morganatic marriage of the royal family of Württemberg, was the elder son of Albert's aunt, Princess Florestine of Monaco.
[1][2] However, given the bitter relations between France and Germany at that time – a socio-political legacy of the Franco-Prussian War of 1870–71 and then of World War I – France deemed it unacceptable for a country over which it had exercised de facto or de jure hegemony, intermittently since the 17th century and consistently for half a century, to fall into the hands of a German aristocrat.
[1][5] Moreover, while the House of Grimaldi had close ties to France due not only to geographical proximity, but also to possession of estates (vaster by far than the territory of the principality) and financial investments there, nothing officially prevented the dynasty's political or cultural associations from focusing elsewhere.
Moreover, the hereditary principle allocated monarchies according to one form or another of proximity of blood, and the Grimaldis' hitherto exclusive control of Monaco's dynastic marital policy was what threatened to enthrone a German duke on France's border, even after the Empire's defeat in war.
[6] Although the Grimaldis did not require inter-marriage with royalty by law as German dynasties typically did, by custom they never married subjects of their own realm, and no Monégasque reigning prince or heir had wed a French consort in more than a century.
[7] This led to the end of absolutism, at least on paper, and also as a part of the overall resolution the Duke of Urach's claim was relegated behind that of Albert's newly recognised granddaughter Charlotte Louvet (see below).
[8] While the adoption process was underway, and given the failures of the German spring offensive and the Second Battle of the Marne, France persuaded Prince Albert to sign a restrictive treaty in Paris on 17 July 1918.
"[9] Charlotte was formally adopted by her own father Louis at the Monégasque embassy in Paris on 16 May 1919, in the presence of her grandfather Albert I, the French president Poincaré, and the mayor of Monaco.[who?]
[8] Charlotte was created Duchess of Valentinois by Albert I on 20 May 1919, and on 1 August 1922, following Louis II's accession on 26 June of that year, she was officially designated the Hereditary Princess of Monaco as her father's heiress presumptive.
[2][4] The count was a more remote, female-line descendant of the Grimaldi dynasty, and was next in line to the Monégasque throne after the Urachs according to the pre-1920 order of succession.
[10] In 1930 the Chicago Daily Tribune reported that Wilhelm's third son Prince Albrecht had met with French officials in Paris, hoping to be approved by them as Louis' heir.
'[11] Prince Albrecht could argue that his mother was descended from Louise Élisabeth of France, and so considering the Treaty of 1918 he was more French than his father, and had been educated in Paris.
[8] In 2018, Count Louis de Causans sued the French government for US$401 million alleging that France used a "sleight of hand" to deprive Duke Wilhelm II, his ancestor, of the Monegasque throne when it passed the 1911 law permitting Charlotte to be considered a Grimaldi.
[12] "A German reign over Monaco, on the eve of the First World War was simply unacceptable for France" said the count’s lawyer, Jean-Marc Descoubès.