“Anna Ball” (dance party) is held traditionally on Anna's day in a Hungarian resort town. The event also marks the end of the first phase of the bathing season.
The custom started in Balatonfüred on July 26, 1825 by Szentgyörgyi Horváth Fülöp János; only Balatonfüred city council can authorize a ball under this name on this day in Hungary.
In the 19th century, this dance party was the most popular among the aristocracy and many celebrities took part in the event, among them Mihály Vörösmarty, Mór Jókai and Lujza Blaha. Anna-balls were held more or less regularly, but not every year. The name of the first elected prom queen was Irma Kozma in 1862.
(wikipedia – hungarianambiance.com)