Complex sentence: Frederick Campbell was the third son of John Campbell, 4th Duke of Argyll, and his wife, Mary, daughter of John, 2nd Lord Bellenden, and was Member of Parliament for Glasgow Burghs from 1761 to 1780 and for Argyllshire from 1789 to 1799.
Split into simpler sentences: Frederick Campbell was the third son of John Campbell, 4th Duke of Argyll, and his wife, Mary, daughter of John, 2nd Lord Bellenden. He was Member of Parliament for Glasgow Burghs from 1761 to 1780 and for Argyllshire from 1789 to 1799.