Complex sentence: The 1st Marquess was one of the few people to become a Marquess without inheriting any titles prior to the creation, sat in the British House of Lords as one of the twenty-eight original Irish Representative Peers from 1800 to 1821.
Split into simpler sentences: The 1st Marquess was one of the few people to become a Marquess without inheriting any titles prior to the creation. He sat in the British House of Lords as one of the twenty-eight original Irish Representative Peers from 1800 to 1821.