"...critical moments when the Great Detente began to fully break apart and the Iron Triangle of France, Austria and (theoretically) Denmark began to look very valuable to Parisian policymakers once again.
The Serbian Question was, on its own, not a particularly difficult solution on paper. The Obrenovic dynasty had been run out of its own country through ineptitude, corruption and deep unpopularity; the Austrian intervention in the subsequent civil war had been a headache and embarrassment. However, the longstanding Serbian rival to the now-exiled house, the Karadordevics, were an unacceptable imposition to Austria, and otherwise sympathetic states like Germany, Britain and the Ottomans were not particularly enamored with the idea of the family who had married into the Romanovs - Prince Petar Karadordevic's daughter, Yelena, had married Grand Duke Kirill Vladimorivich, the likely heir to the Russian throne in the unlikely event Tsar Michael II ever had a legitimate son - on the throne in Belgrade, a set of circumstances which would scramble the status quo of the Balkans and, more critically, reorient Russian attention back to Europe after three decades of "looking East."
The Congress of Budapest was, thus, a typically post-1815 response to the problem. The Great Powers would gather in Hungary, hash out an agreement that everybody could be satisfied with even if they did not love it, and wash their hands of the matter. The Serbians, as an impoverished minor power on the European periphery, would of course not be invited and simply expected to accept whatever deal the Concert of Europe arrived at. The Congress was, unsurprisingly as these things went, dominated by the British. The Marquess of Crewe, London's foreign secretary, began the lengthy negotiations with a quip about how "there's always a German prince floating around somewhere" and then began to take temperatures on who, exactly, the other European powers - many of whom had not even dispatched their most-senior diplomat, so irrelevant was the Serbian succession regarded - could accept.
France was unique in that Emperor Napoleon V, nobody's idea of a diplomatic heavyweight (or a heavyweight in any subject, for that matter) insisted to his government upon attending himself. This served as an enormous detriment to the proceedings; Napoleon's consistent demand was that the throne be handed off to Wilhelm, the Duke of Urach. This was of course no coincidence - it was Wilhelm who had far and away the best claim to the throne of Monaco as heir to Louis, the tiny principality's new sovereign installed in 1912 after his father's forced abdication by street riots. To Napoleon (or, more likely, his advisors in the Tuileries and Quai d'Orsay), tying Monaco to Serbia made a certain type of crude, logical sense. In Wilhelm there was a potential new ruler of Serbia who they could in one swoop get off their borders and into Belgrade, thus settling Austria's Serbian problem while solving their own Monegasque one. It all made sense, but for the fact that it was laughably transparent what Paris was trying to accomplish.
The Duke of Urach was, by all accounts, a fairly liberal noble whose pledge to honor Monaco's newly promulgated democratic constitution would certainly have carried over to Serbia, which for all its problems had a corrupt and chaotic but on paper functional constitutional monarchy dating back to the early 1890s. He was also not particularly ambitious about either throne, and accepted his candidacy at Budapest with the same shrugging acquiescence he did for his claim to Monaco's crown. None of this aided his case. Austria, for starters, was aghast at the implication of what Napoleon was suggesting - in what universe was a minor German duke appointed to the monarchy of Monaco a threat to France, but that same man, if made King of Serbia, not one to Austria? If Wilhelm was an unacceptable choice on French borders then he, on the frontier of Austria, with its great South Slavic population and extant issues taming nationalist impulses within its own polity, was completely out of the question. Franz Ferdinand, representing his uncle along with Count Leopold Berchtold, the Dual Monarchy's Foreign Minister, denounced the idea in no uncertain terms behind closed doors - to delegates of all assembled parties. "We will not be the sacrifice to wounded French pride!" he thundered angrily, according to one account. This had the added impact of creating a substantive breach in the Franco-Austrian position and, with both Paris and Vienna dismissive of considerable and understandable Ottoman concerns regarding Serbia's ruler, finally breaching the close political partnership between the Porte and the Habsburg-Bonaparte alliance that had persisted over three decades. The Ottomans, relegated to Budapest's sidelines, took the snub as a grievous insult and withdrew from European affairs for a period of a few years.
This breach at Budapest was apparent to others, too. Germany, Britain, Russia, Italy - all could see the palpable disgust Austria had for its treatment as a disposable, irrelevant junior partner at France's hand. This greatly strengthened their position, too. Germany and Italy produced the solution that eventually won the day - Prince Mirko of Montenegro, the second son of the reigning king, Nikola. The "spare" of the royal house of Montenegro had certain appealing advantages: Montenegro had long been in the Franco-Austrian sphere of influence and Nikola was seen as a friendly and experienced ruler; the Francophile Mirko was also married to a distant descendant of the Obrenovic line but his wife was not known as one of the dynasty's partisans amongst European society; while proud Serbian patriots, they were not known to be adherents to the idea of a Greater Serbdom and its associated irredentist strain of thought. Whatever qualms Austria may have had about the same family ruling the two independent South Slavic kingdoms in the Balkans was allayed by Russia's acquiescence to this arrangement and an Anglo-German insistence on the conclusion of the conference post-haste forced the Austrians, in their second capital, to swallow a deal they weren't particularly happy with but was better than the insult bandied about by Napoleon.
The Congress of Budapest, while contemporaneously seen as having "solved" the Serbian Question, is today regarded by most scholars of the Central European War as a disaster; British historian Charles Reynolds once described it as "the Blunder of Budapest." The attempted French ploy to gin up fears of the Duke of Urach in miniscule Monaco and "foist him unwillingly upon Austria as head of a much more concerning state" was not soon forgotten in Austria: consequently, particularly after the death of Franz Josef in November of 1916, a suddenly very isolated France went to tremendous lengths to prove its mettle to its Austrian ally, a fateful circumstance when the Hungarian Crisis erupted at the end of the decade. Budapest may have threatened to completely break the Iron Triangle, were it not for the Tuileries' desperation to maintain it: rather than scramble central Europe's oft-fragile and fluid alliance blocs, it merely hardened and intensified them, without removing the bizarre and trivial dispute over Monaco that had for reasons of pride and ambition become a defining, red-line feature in Franco-German relations.
It also created a tremendous amount of sympathy in foreign courts for the Magyars, particularly the nationalists. Everyone found something to like - liberal Britons in the enthusiasm of its activist parliamentarians who seemed to evoke a modernized spirit of 1848, to the Russian empathy towards the autocratic magnates who really ran the place. Important Hungarian leaders, heretofore focused almost exclusively on domestic matters with Franz Josef selecting who exactly was dispatched as diplomatic envoys abroad, built key contacts and friendships with foreign dignitaries, policymakers, and most importantly journalists. The result was that sympathy for Hungary in the European elite soon became sympathy for Hungary in the European public, particularly in Germany, a turn of events that would greatly color how Europe responded to the looming storm clouds on the horizon..."
- The Central European War