Complex sentence: Wartensleben's army retreated behind the Naab River on 18 August and, as Jourdan closed up to the Naab, he posted Jean-Baptiste Bernadotte's division at Neumarkt in der Oberpfalz to observe Charles.
Split into simpler sentences: Wartensleben's army retreated behind the Naab River on 18 August. As Jourdan closed up to the Naab he posted Jean-Baptiste Bernadotte's division at Neumarkt in der Oberpfalz to observe Charles.