Complex sentence: Paykull then marched with his combined Saxon-Polish-Lithuanian army against Carl Nieroth's force protecting Warsaw--the both armies clashed near Warsaw, just five days after the battle of Gemauerthof.
Split into simpler sentences: Paykull then marched with his combined Saxon-Polish-Lithuanian army against Carl Nieroth's force protecting Warsaw. The two armies clashed near Warsaw, just five days after the battle of Gemauerthof.