Complex sentence: It served as a summer resort for Empress Dowager Cixi, and 3 million taels of silver, said to be originally designated for the Chinese navy (Beiyang Fleet), went into the reconstruction and enlargement of the Summer Palace.
Split into simpler sentences: It served as a summer resort for Empress Dowager Cixi. Three million silver taels, said to be originally designated for upgrading the Qing navy, the Beiyang Fleet, were used for reconstructing and enlarging the Summer Palace.