Complex sentence: One of the teachers of French was, since October 1810, Nicolas Chopin, the father of Frédéric Chopin, who was one of the most famous pupils, beginning his studies there in the autumn of 1823.
Split into simpler sentences: One of the teachers of French language was, from October 1810, Nicolas Chopin, father of Frédéric Chopin. The young composer was one of the Lyceum's most famous pupils, beginning his studies there in the autumn of 1823.