Complex sentence: In 1811, at the age of 14, Jacob Fredrik Ljunglöf started working at a large tobacco factory, which he in 1821 took over, starting to produce snus under his own name.
Split into simpler sentences: In 1811, at the age of 14, Jacob Fredrik Ljunglöf started working at a large tobacco factory. In 1821 he took over the same factory, starting to produce snus under his own name.