Charles Allen helped unite ITV following the merger of Granada and Carlton in 2004, but has been under pressure ever since after taking on the role of chief executive at the UK's largest commercial broadcaster.
The outgoing chief executive started his career as an accountant at British Steel. He later joined contract caterer Compass where he met Gerry Robinson, who would become his mentor, and the pair moved to Granada - the owner of the ITV franchise in the north of England - in 1991.
As chairmann of Granada, Mr Robinson oversaw its merger with Compass in 2000 and its demerger in 2001, which split the business into a catering and hospitality company and a media company focused on Granada's TV interests.
Following the split, Mr Allen took over as chairman after Mr Robinson stood down and focused his energy on consolidation in the sector, winning a reputation as a strong tactician.
The ITV network was a place of intrigue and Mr Allen was involved in a number of high-profile struggles with other regional bosses.
He famously won a battle with Greg Dyke, which led to the former BBC director-general losing his then job as chief executive of London Weekend Television following a takeover by Granada.
One of Mr Allen's greatest achievements was pulling off the merger of Granada and Carlton to create a cohesive group for the first time since 1955, when the old network of regional franchises went on air.
Mr Allen has also been praised for driving down costs and beginning the process of moving away from the reliance on ITV1 by launching new digital channels and creating income streams from acquisitions such as the Friends Reunited website.
But his critics say he is a numbers man who has lacked creative vision.
ITV1's reliance on reality television has proved unpopular.
Celebrity Wrestling is one of the channel's biggest flops, while Love Island has failed to draw in the viewers. In July, It's Now Or Never, fronted by Phillip Schofield, was dropped after one episode.
And while ITV1 has had a number of hits, viewing figures are at an all-time low. Five times as many football fans watched the BBC's coverage of the World Cup in Germany as tuned in to ITV's.
He had come under pressure from low viewing figures and declining advertising revenues at the company's flag-ship channel ITV1.
Shareholders had also been concerned he has been slow to respond to new media's challenges and chances.