Brock obtained a Master of Arts in Modern History from Corpus Christi College, Oxford in 1973.

Since beginning his career in 1973 as a reporter for the Yorkshire Evening Press, Brock was a journalist for The Observer (1976—1981) and The Times (1981—2008), where he held positions from foreign correspondent to managing editor.

Brock has been President of the World Editors Forum (2004—2008) where he still sits as a board member. He was also a member of the board for The Times Newspapers Ltd (1997—2004) and has frequently written for papers in the US, Poland, and Sweden.