Complex sentence: The Third Marquess of Bute had inherited Castell Coch in 1848, along with enough land and dosh to make him "one of the wealthiest men in the world", and he had the castle rebuilt by William Burges for use as a summer home.
Split into simpler sentences: The Third Marquess of Bute inherited Castell Coch in 1848, along with enough land and money to make him "one of the wealthiest men in the world". Later, Bute had the castle rebuilt by William Burges for use as a summer home.