The crowning achievement of his 23-year term was the 1896 millennium celebrations, lasting from 2 May to 31 October, commemorating the anniversary of the Hungarian conquest of the Carpathian Basin. Organized by the Hungarian state, the City Park was the main venue for the events. The celebrations became the symbol of the Golden Age of Budapest, which corresponded with Kamermayer's terms as mayor. Within the project, the construction on the first metro line began in 1894. Completed by the deadline, it was inaugurated on 2 May 1896 by Francis Joseph. It is the second oldest underground railway in the world (the first being the London Underground), and was the first on the European mainland.