Complex sentence: He triumphed over the Russians and Alexander Korsakov at the Second Battle of Zurich in September, then, aware of the advance of Russian general Alexander Suvorov toward St. Gotthard, quickly shifted his troops southward.
Split into simpler sentences: He triumphed over the Russians under Alexander Korsakov at the Second Battle of Zurich in September. Masséna, aware of Suvorov's advance toward St. Gotthard, quickly shifted his troops southward.