Henry resigned this week from United London. He co-founded Howell Henry Chaldecott Lury in 1987, which became United in January after several rebrandings. He was the last of the founders still at the agency.
Henry's defection coincides with the resignation of Amanda Walsh, United's European president, who is leaving at the end of the month. Her role as a network chief has been diminished after United slimmed down from a 60-strong network to one with only nine outposts.
Henry will complete a senior TBWA management team composed of the chief executive, Matt Shepherd-Smith, and the chairman, Neil Dawson. He effectively replaces Trevor Beattie, who left the agency last year to launch Beattie McGuinness Bungay.
Henry will head TBWA's creative department, which is currently overseen by the joint creative directors, Danny Brooke-Taylor and Tony McTear. The pair will report to Henry.
Shepherd-Smith said: "Steve is an exceptional creative talent and loves to challenge the status quo. He embodies our philosophy of 'disruption' and will be a great addition. We can't wait for him to join us."
Henry added: "This is an irresistible opportunity. I love the people. I love the client list, but, most of all, I love the agency's philosophy of 'disruption'. It is better prepared than anyone else to embrace the challenges of a multi-disciplined future."
Meanwhile, Walsh leaves United without a job to go to. She said: "I've had a great time at United and am really proud of what we have achieved. However, I am ready to move on to new challenges.
"You do not need two chief executives to run a micro-network. It is right and proper that Andy [Berlin, the global chairman and chief executive of the United network] stays as sole leader."
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