Complex sentence: He separated from Elisabeth in 1839 and moved to Brussels, and around 1841 moved to Warsaw where he is believed to have conducted the Teatr Narodowy (National Theatre) orchestra.
Split into simpler sentences: He separated from Elisabeth in 1839 and moved to Brussels,. Around 1841, Litolff moved to Warsaw, where he is believed to have conducted the Teatr Narodowy (National Theatre) orchestra.