Last time around - in May 1896 - the cause for celebration was the opening of the first underground line in continental Europe, presided over by Emperor Franz Josef I of the Austro-Hungarian Empire.
This time, late last month, the festivities were occasioned by the reopening of the line after a six-month closure for much-needed renovations and a facelift aimed at recreating some of the original fin-de-siecle grandeur.
Instead of an emperor, the city mayor, Gbor Demszky, led the procession of Budapest's great and good who boarded the first trains out of the revamped Vorosmarty Square station and marvelled at the handiwork: freshly tiled walls, hand-painted station signs and oak-panelled ticket booths. At the end of the line horse-drawn carriages were waiting to take the revellers on to another of the city's most famous turn-of-the-century establishments, the similarly restored Gundel's restaurant.
The primary purpose of the underground renovation work was to repair more than 40 years of Communist neglect. In the first flush of post-Communist freedom, the line had increasingly been targeted by vandals. The city authorities also deliberately set out to recreate some of the flair and feel of 99 years ago.
At the time of its original construction, the Budapest underground was the first on the continent (the first in Europe was in London), and its opening was one of the many events arranged in conjunction with the 1896 millennium celebrations, marking the 1,000th anniversary of the Hungarian settlement in central Europe.
It was a seemingly glorious moment in the country's history. Under the historic compromise reached with Austria just 29 years earlier, Hungary had a joint stake in a vast empire and itself ruled over millions of Croats, Serbs, Romanians and Slovaks. Economically and culturally the country was flourishing, and nowhere more than Budapest, which was reaching the high point of an artistic and architectural boom.
In addition to the underground, the later years of the 19th century saw the building of boulevards of grand apartment blocks, an opera house, an extension of the city's castle and the neo-Gothic parliament: all of which continue to lend the city its elegance and charm.
By 1896, Budapest had risen from a nondescript town 140 miles east of Vienna to a European metropolis. There were still almost 20 years to go until the cataclysm of the First World War, which spelt the end of the Austro-Hungarian empire and saw Hungary itself being forced to cede some two-thirds of its territories.
Not surprisingly, there are many Hungarians who see the turn of the century as a golden era. Shortly after I arrived here my landlord thrust into my hands a map of Hungary in its pre-1914 borders - just in case I was unaware of the tragedy that had befallen his nation. The equivalent in Britain - handing out maps to foreigners depicting the empire at its peak - would be virtually unthinkable.
For the ordinary Hungarian riding the millennium metro, thoughts of empire are very distant. Most people are preoccupied with scraping together an existence, and are just hoping that public expenditure cuts will not hit them. If there is a goal in these post-Communist days it is Brussels: twin seat of Nato and the European Union, the two institutions now seen as the panacea to many of the country's pressing problems.
The freshly-painted tiles and the pretty wooden panelling on the underground have certainly enhanced commuter travelling, and have been welcomed by the tens of thousands who see them each day. For most people here, however, the real hope is that, rather than serving as a reminder of an almost mythically glorious past, they might just be a signal of better times ahead.