Complex sentence: Diane Allardyce James (born 20 November 1959) was the leader of the UK Independence Party (UKIP) for 18 days between September and October 2016.
Split into simpler sentences: Diane Allardyce James (born 20 November 1959) is a British politician. She was the leader of the UK Independence Party (UKIP) for 18 days between September and October 2016.