Leopold Popper was from a humble background, but thanks to his exceptional business talent, he went a long way in life. He did business in the wood trade and his company was very successful; it was one of the biggest in the country. It apparently also supplied material for the construction of the Suez Canal. He invested some of the money he earned into the purchase of real estate. For example, he bought the entire Bytča-Strečno estate from the Esterházy family, thus also acquiring Strečno castle. In 1869, Leopold was promoted to the rank of Hungarian noble for his merits in developing the economy, mainly forestry and agriculture, and for his support for the poor in Hungary. In 1882, he was also awarded the Order of the Iron Crown – second class – and rose in rank to that of Freiherr as Baron Popper von Podhrágy. By the end of his life, he was one of the wealthiest citizens in the entire monarchy. In the course of his life, he also supported social life in Bytča, for example by having a Jewish school built there.
