When he starts next week, Hopson will manage the group’s biggest account, Volkswagen, as well as take responsibility for developing the group companies, including the digital agency Tribal, the production arm Gutenberg and the content division Cain & Abel.
Hopson will report to James Murphy, the founder and chief executive of Adam & Eve/DDB, with whom he worked, alongside two of the other founders, Ben Priest and David Golding, at Rainey Kelly Campbell Roalfe/Y&R.
After running Team Red, the interdisciplinary group for Vodafone, from 2011 to 2013, Hopson worked on a number of international projects for WPP. He left the group in May last year.
At RKCR/Y&R between 2005 and 2011, Hopson led the Virgin Atlantic, Virgin Media and Bacardi accounts. Murphy hired Hopson as a group account director before promoting him to deputy managing director.
Hopson became the managing director at RKCR/Y&R in July 2007 ahead of the departure of the Adam & Eve/DDB founders and rose to group managing director in 2010.
Murphy said: "Russell is a really good team-builder. He’s very smart, both strategically and creatively, and ego-free."
Havas London hired Rees as its chief executive in March.