John Williamson, who has died aged 79, was a major player at Wolff Olins for nearly three decades, instrumental in bringing the agency out of the 1990s recession and transforming it into one of the best-known corporate identity consultancies. “If organisations have one human being who they regard as the embodiment of their intelligence and their philosophy, in my days at Wolff Olins that was John,” says Michael Wolff, who co-founded Wolff Olins with the late Wally Olins in 1965.