LONDON—Public affairs veteran Charles Stewart Smith, co-founder of Luther Pendragon, GPlus Europe and Silk Public Relations, is joining Blue Rubicon as a director.

Stewart Smith will work across the Blue Rubicon family of brands, and will provide support to Thirty Six Strategy, the firm’s strategy consulting arm, which is led by Spencer Livermore.

According to Blue Rubicon senior partner Fraser Hardie, Stewart Smith “has launched and built three very different, highly successful agencies, advised clients at the highest levels, worked in broadcast journalism at the top of the profession and served as chairman of influential organisations such as Editorial Intelligence.” He has also served on Blue Rubicon’s advisory board for several years.

Stewart Smith was co-founder of UK-based corporate and public affairs consultancy Luther Pendragon which he sold to a management buyout in 2005; Brussels public affairs firm GPlus Europe, which he sold to Omnicom in 2005; and Silk Public Relations which he sold to Focus Public Relations in 2005. Since those sales, he has been an independent consultant, been active in a number of charitable endeavors, and served as chairman of Editorial Intelligence and wealth management business Edison.