Complex sentence: Graham-Dixon began work as a reviewer for the weekly "Sunday Correspondent", before becoming the chief art critic of "The Independent" newspaper where he remained until 1998, and as of 2005 is the chief art critic of "The Sunday Telegraph".
Split into simpler sentences: Graham-Dixon began work as a reviewer for the weekly "Sunday Correspondent", before becoming the chief art critic of "The Independent" newspaper where he remained until 1998. As of 2005 is the chief art critic of "The Sunday Telegraph".