Complex sentence: Radványi studied economics and philosophy in 1918-1919 at the University of Budapest, where he became involved in radical politics and with the destruction in 1919 of the Hungarian Soviet Republic fled to Vienna, Austria.
Split into simpler sentences: Radványi studied economics and philosophy at the University of Budapest from 1918-1919, where he became involved in radical politics. With the destruction of the Hungarian Soviet Republic in 1919, he fled to Vienna, Austria.