Europe's royalty gathered in Vienna on Saturday for the funeral of Otto von Habsburg, the last heir to the Austro-Hungarian empire.

Vienna's archbishop Cardinal Christoph Schoenborn celebrated a funeral mass at St. Stephen's Cathedral for Habsburg, who was born a prince six years before the Austro-Hungarian empire fell in 1918. He died earlier this month at his Bavarian home in Germany at the age of 98.

For some Austrians, his passing has evoked a sense of nostalgia for the Habsburg empire, although others mocked the outpouring of emotion. Members of historical societies wore traditional uniforms and carried embroidered banners at the funeral.

Guests at the mass included King Carl Gustaf and Queen Silvia of Sweden, Grand Duke Henri of Luxembourg, Prince Hans-Adam of Liechtenstein and former monarchs and representatives of the Romanian, Bulgarian, British, Spanish and Belgian royal families. Some European leaders also attended.

Habsburg was the eldest son of Austria's last emperor, Charles, who ascended the imperial throne in 1916. But the empire broke apart two years later after defeat in the first World War.

As the empire fell, Habsburg was exiled to Switzerland along with his family, but relinquished his own claim to inherit the empire in 1961. After much political and legal wrangling, he was allowed to return to Austria five years later.

He was an ardent anti-Nazi, speaking out against Germany's annexation of Austria in 1938, and later a staunch foe of communism. He served for two decades in the European Parliament and during that time helped organize the “Pan-European picnic” near Hungary's border with Austria, during which about 700 East Germans escaped to the West months before the fall of the Berlin Wall.

Habsburg's body is being buried in the Imperial Crypt in Vienna alongside that of his of wife, Regina, who died last year, and near dozens of his ancestors who ruled for more than seven centuries.

But his heart, according to Habsburg tradition, is being taken to Hungary for burial Sunday in an abbey west of Budapest.