Complex sentence: This was only after furious street fighting in the Battle of Lübeck, in which he led some of the cavalry charges himself; the exhausted Prussians had, by the time of the surrender, neither food nor ammunition.
Split into simpler sentences: This was only after furious street fighting in the Battle of Lübeck, in which he led some of the cavalry charges himself. By the time of the surrender, the exhausted Prussians had neither food nor ammunition.